El Camino Central Forum banner

1 - 20 of 59 Posts

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #1 (Edited)
Conversion to Hydro Boost Brake System - 1970 El Camino

I am not an expert, so this is intended to only present some thoughts and ideas from a novice that you would need to research and verify prior to putting on your brake system. Your brakes are important so please verify first.


Problem Statement: Blower cam does not allow engine to produce enough vacuum for power brake booster to be effective. This can occur on high overlap “cammy” high performance engines, those with forced induction, and those with turbo. My current engine set up produces 10 to 13 inches of vacuum at sea level. Rather than vacuum, boost is produced when RPM ramps up. Brakes are not functioning well. Inconsistent pedal pressure required. Sometimes marginal, other times no assist at all, requiring “standing” or “two footing” brake pedal to stop.

Goals: Produce improved and consistent power brake assist. Stop prior to the rear bumper of the car ahead.

Options: Considering new parts and some labor cost estimates
1) Change camshaft to a milder cam that allows vacuum above 18 inches
PRO: Affordable at about $300-500
CON: Changes character of car and performance
2) Convert to manual brakes
PRO: Affordable at about $200-400 (depending on selected master cyl)
CON: Not many that I see. If done right, this is a viable solution
3) Add a vacuum reservoir (or increase booster size)
PRO: None for situation of not producing enough vacuum
CON: Not a viable solution when minimal vacuum produced
4) Add electric vacuum pump to current system
PRO: Affordable at about $300-400
CON: Noisy, with vibrations (yet I would not hear it with Flow Master 40s and 3 inch exhaust)
Many I spoke who used this solution removed it later
5) Replace vacuum booster with Hydro Boost
PRO: Provide higher pressure to brake calipers and stopping capabilities
Will support later upgrades to bigger brakes with more calipers and higher flow/pressure
Increases clearance for tall valve covers (not a problem for me, I am not “big block”)
CON: $800 – 2000
May expose weak points (lines, caliper leaks) in current brake system
May expose weak points (leaks, low volume, marginal pump condition) in power steering
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #2 (Edited)
Selected Implementation
Replace vacuum booster with Hydro Boost
PRO: Provide higher pressure to brake calipers and stopping capabilities
Will support later upgrades to bigger brakes with more calipers and higher flow/pressure
CON: $800 –2000
May expose weak points (lines, caliper leaks) in current brake system
May expose weak points (leaks, low volume, marginal pump condition) in power steering

Purchased the following as a kit 3014 (or 3013 with older master cyl) for disk/drum or disk/disk:
Various similar kits available from HydraTech CPP  Summit
http://www.hydratechbraking.com/GM_A_Body.html
• Bosch Hydro-Boost hydraulic booster unit (select long or short rod depending on your master cyl)
• HydraTech custom 68-72 A body billet aluminum direct fit firewall mounting plate with 6 degree upward tilt, No changes to firewall required with this kit. Other kits have 17 degree upward tilt (like stock) for more clearance if needed
• Adjustable brake pedal rod to allow for a range of brake pedal height adjustment
• Chrome Corvette (1977-82) style master cylinder 1 1/8 inch bore (in some kits or as an option)
• Stainless high pressure brake and rubber low pressure kit with connectors (in some kits or as an option)
It is important to match the short/long rod length to your master cylinder.
I am using the 3014 kit with short rod with a newer style master cylinder. (Some how this was not correct, yet the MC had an "extension" for the rod)

It is important to match the Master Cylinder(MC) bore diameter.
Kits 3513/3514 have a 17 degree bracket providing more booster/MC clearance if needed.


Shear Performance, in Costa Mesa California, will be making the following changes during the install.

Create custom hoses using Parker high pressure black mesh wrapped hoses (2,300 PSI) and a lower pressure black mesh for return hoses. Our preference, yet you can use the stainless steel high pressure lines.
PRO: My personal preference for black mesh hoses
Will not scratch engine compartment components like stainless hoses tend to do
Justin Shears prefers them (I place value in using what they trust not to leak)

Modify existing Saginaw power steering pump reservoir to accept a second PS fluid return line,
Convert the return line fittings from barbed to AN fittings.
Use Delco PS fluid (not ATF for Hydro Boost)
PRO: More efficient
Reduces problems from adding a T splitter that has caused brakes to hang/drag/chatter
AN fitting should handle pressure better than barbed connections
Requires replacing power steering fluid, keeping old contaminants out of the new brake booster

Reuse of the existing A body master cylinder allows the install to occur without opening the brake (fluid) system.

Replace old MC with new MC. There is evidence that current or a prior master cylinder leaked. Since we need to check for brake fluid leaks at each wheel, we may as well change/purge/bleed the brake fluid. The natural, rust colored patina of the existing MC is a distraction when the hood is opened. It may be less labor to install the new one than clean/prime/paint the existing one. The kit I purchased had the new Corvette style MC included, so Shear Performance will swap it out.

We will reuse the 1970 distribution block (like a proportioning valve) and separate brake light alarm sensor mounted to the frame.
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #3 (Edited)
Images below include:
1) Booster can be mounted by rotating if additional clearance needed.
Not required to be rotated for our install.
Although not installed in this image, I have a chrome cover for the cylindrical nitrogen reservoir.
The pressure from the power steering fluid “charges” the cylindrical nitrogen reservoir.
The reservoir provides the assist and a short term backup if the engine stalls or there is a loss of power steering pressure.

2) HydraTech 6 degree A body mounting bracket and Bosch Hydro Boost booster.
An optional 17 degree mount is available from HydraTech for more clearance (not shown in images).

3) Before image, showing vacuum booster
You know what the ugly huge booster looks like.

4) After image showing new HydraTech bracket, Bosch booster and new MC

5) An abundance of room

6) After image showing new hoses from power steering pump to brake booster and back to reservoir.
 

Attachments

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #4 (Edited)
Can you do this on your own?
Maybe not me. However, many of those on El Camino Central have the skills to do this kit modification.

What else is important?
These are your brakes. I am not a mechanic, so I used a very good mechanic familiar with this customization. In fact Justin’s Chevelle has this system.
http://www.shearperformanceinc.com

Do not skimp on the hoses, fittings and assembly. Very high pressure quality hoses with good fittings are required. Leaks would be bad enough, yet under pressure, you could “paint” your engine compartment in power steering fluid and risk fire and loss of power assist. Expect $225 to $300 for hoses and fittings.

Use Power Steering Fluid, not ATF. ATF foams more which is not good for Hydro Boost systems.

If you have high vacuum, you should be able to correct your power vacuum assist system. Hydro Boost does not magically fix other brake system problems.

DStinch has a very similar engine/blower set up to me. Don is happy with his electric vacuum assist solution (not a Hydro Boost solution).

What happens if I break a power steering hose?
If you are turning, it will be more difficult, just as your power steering would be before adding Hydro Boost.

The Hydro Boost system above uses a booster that includes a nitrogen cylinder.
The nitrogen cylinder stores energy that assists in the brake boosting. The cylinder normally assists every brake application. Should a power steering hose hose break or an engine stall, the nitrogen cylinder provides assist to the next three brake applications at declining levels. As the assist level reduces you should become aware of the difference in brake pedal feel. Then the brakes go to a level not too dissimilar from manual brakes. As long as your brake master cylinder, lines and system are in tack, you will need to apply considerably more foot pressure on subsequent stops.

Did we find weak spots during our install?
Yes. Replaced the 45 year old rubber brake lines at the four wheels (appox 12 inches long). The old ones where brittle and cracked. They were close to the point of failure with the old system, let alone with the new higher pressure.
Replaced right rear brake cylinder that ended up leaking.
Replaced left rear brake cylinder that was jamming.

SHOW ME installation video resources
V8TV HydraTech install Part 1 and Part 2
https://www.youtube.com/watch?v=pTNlwDlesdw
https://www.youtube.com/watch?v=zj73htdt87Y
Popular Hot rodding CPP Hydra Stop Brake Booster
Note: Prices have escalated since video released.
https://www.youtube.com/watch?v=d3bBiY5ot18
Matt Sweeting Power Brake TV
https://www.youtube.com/watch?v=qNkuJZUXqf8

A different FAQ
Hydratechbraking.com FAQ
http://www.hydratechbraking.com/FAQ.html

Can I get used parts for less?
You will need to adjust pedal lever location, make mount for firewall, match booster to MC, obtain or make quality hoses, etc.
1983 El Camino diesel had Hydro Boost. (Thanks JLCustomZ)
Some Chevy Astro Vans
Some 88-98? C/K250 and C/K350 Chevy trucks
Some motorhomes

Any references for going recycled parts?
Car Craft - Chevy Astro Van Hydroboost Salvage - Junkyard Builder
http://www.hotrod.com/how-to/chassis-suspension/ccrp-1105-chevy-astro-van-hydroboost-salvage/#ixzz3X7wLSHd1
NastyZ28 Forum
http://www.nastyz28.com/forum/showthread.php?t=215789
Bangshift.com How to Swap a Junkyard Hyrdoboost on Your Classic GM Muscle Car or Truck
http://bangshift.com/general-news/tech-stories/tech-how-to-swap-a-junkyard-hyrdoboost-on-your-classic-gm-muscle-car-or-truck/

Any other El Camino Central Threads on Hydro Boost?
http://www.elcaminocentral.com/archive/index.php/t-15167.html
http://www.elcaminocentral.com/archive/index.php/t-73489.html
 

·
Registered
Joined
·
125 Posts
Great write up! Very happy with my set up also. I will add that on my set the up two things drove me crazy trying to figure out was if you use a gen 2 pump you must change the fitting on the pump to reduce the flow or you will aerate the system. The other was to use royal purple ps fluid.
 

·
ZERO MPG
Joined
·
15,362 Posts
I have a Hydro boost system for sale $175.00. I would buy new lines but works fine the way it sits.I'm in Los Angeles.







 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #8
Robert,
Was yours pulled from your '85 before the rebuild, or which donor vehicle? Astro, C/K etc.
 

·
ZERO MPG
Joined
·
15,362 Posts
Robert,
Was yours pulled from your '85 before the rebuild, or which donor vehicle? Astro, C/K etc.
It was out f a 1972 something??? If you want to try it then buy it that's fine with me????
 

·
Registered
Joined
·
351 Posts
Mine had the original hydroboost (diesel) and 2 replacements leaked so I went back to reg. power brakes. I had to change the pedal because the pin is in a different location. To help with the vac. I put in a vac. pump, there is a tee in the line so if vac. pump quits working the brake booster still has engine vac. Also the pump shuts off when it is not needed.

Don
 

·
Deputy Director Region 6 - Supporting Member
Joined
·
6,210 Posts
Gale the 6 degree vs 17 degree part was confusing me a bit. Finally figured that more clearance with 17 degrees must mean clearance from such as big block valve covers or other engine components. From appearance the overall length of this unit (firewall to front of MC) looks to be longer than standard booster setup. Your opinion on whether the 17 degree angle may cause issues with a 70-72 cowl hood? As in overall heighth when installed :dontknow:.

Thanks! :beer:
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #14 (Edited)
I believe the 17 degree is from the base plate cut to angle the booster/master higher. This helps most when someone has lots of tubes running to turbo or cool air plumbing. That may require a taller hood/rise.

I think some are successfully using the 6 degree on big blocks.
http://www.chevelles.com/forums/showthread.php?t=182409

The length from firewall to end of master on mine is 16 inches. If longer than with the original bracket and booster, it isn't by much. Maybe Robpp or someone will measure for us.

I have tall aluminum valve covers on my small block. There is 5 1/2 inches of clearance from valve covers to the master or booster, so I am fine.

The original 70 disk/drum master and this new Corvette master look like fat burritos. Some Wilwood or CPP aluminum master cylinders look like they might be a little narrower if more space is needed.

I will look and find us an image of a big block using the 6 degree (or similar).

We had one tight place when we installed. We tried to hide the line from booster to power steering under the booster. We could then see that could snag the steering shaft nut near the firewall as we turned the column. Rerouted the lines a little putting the larger high pressure on top. Good to go.
 

Attachments

·
Deputy Director Region 6 - Supporting Member
Joined
·
6,210 Posts
You answered my mixed up question just fine Gale! No apparent heigth issue with closing the hood at the taller angle. I am pretty much an SBC only guy. Some others may benefit from some pics of a BB application who are watching this interesting and informative thread.

:beer:
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #16 (Edited)
As promised, here is a link to images of a big block.
This is Mark Demers' ultra clean Chevelle.
At about 35 seconds into the video, you can see it has more than 4 bolts in the valve covers. I can't tell if they are tall covers or not.
His booster bracket looks like about 6 degrees. His mount and hydro boost came from Power Brake Service (Matt Sweeting).

Matt can probably tell you what angle is used on the bracket for Mark's Chevelle.

Now with that said, other shiny stuff seems to have caused some hood clearance issues for Mark.
https://www.youtube.com/watch?v=rvDgzgLgSx8
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #17
There is another difference in Mark Demers' install.

Notice that mine and his nitrogen cylinders are opposite of each other.
His Hydro Boost unit is rotated 180 degrees from mine.
Notice that his lines come up the fender wells.
Just two different approaches.

1) My install (I hide my hoses)
2) Mark's PBS install (Mark shows his off)
 

Attachments

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #18 (Edited)
Where do I see purchasing a hydro-boost kit adding value?

Someone asked a good question, that I think might lead to a better understanding of the process.

Where do I see purchasing a hydroboost kit adding value?
This may be worth scanning, even if you are going with all used parts.

Each of us is different. The skills of the members and visitors to the http://www.ElCaminoCentral.com vary widely. Some love the hunt for parts, others are better puzzle solver, and some are fine mechanics. The kit that I purchased can help in a number of ways, yet your skills and interest may take you in a different direction.

Of course, there is the new part vs. experienced part decisions. When selecting a kit, be sure to read the fine print to see if the brake assist unit is new or rebuilt. It took a little looking with one vendor before I found out the “NEW” kit had a “REBUILT” brake assist unit. You can choose either, just know what you are getting.

References to “The kit” below refer to the 3014 GM A body kit as I purchased it.
1) The kit provided a machined aluminum bracket that provided the correct angle (did not need to modify the firewall for this bracket, you may if you pull parts).
2) The hose/connector kit provided the brake pedal attachment/adjustment rod from the brake assist back toward the pedal.
3) The instructions included how to move (without drilling a new hole for this kit) the brake pedal connection clevis to the correct whole on the brake pedal lever. The calculations had already been done and the angle of the bracket would cause everything to line up and it is the correct length.
4) The brake pedal attachment included an adjustable section to allow setting the pedal to a level the driver prefers. I adjusted mine to be close to that of my daily driver.
5) Even if you are reusing the existing master cylinder, the bore and rod must be a match. The kit either included the master cylinder with the correct bore diameter or tells you which you need for this kit. Additionally, it specifies the short or long rod that goes between the brake assist unit and the master cylinder. Mine actually had an adapter rod to support either length.
6) You can order some kits with different levels of finish on the components. From black paint, to multiple coats with a clear, powder coat including custom colors, or chrome.
7) Keep in mind when assembling your own parts, that some years used metric and others did not. So when pulling parts you will need to either have the hoses/connections or figure out what they are.
8 ) Some vendors redrill the connections at the brake assist, changing to A/N fittings. Having a matching hose kit can help reduce time in figuring which is which.
9) The kit had the correct connections for the Saginaw pump for GM A Body, so metric did not play into the decisions.
10) The kit had reusable AN fittings, rather than crimped. So if we needed to shorten a hose or reset a connection to the brake assist, we could more easily than using crimped connections.
11) The hose and fitting kit can save a lot of time versus rounding up parts.
12) The kit also comes with instructions. Your experience will cause the value you receive to vary. Even for an experienced mechanic, it can function as a good check list that may improve quality.

The kit contained what I view as a fair price with all the hose/fittings for a good quality install. The skills at Shear Performance include “very skilled auto plumbing”. I admit to pushing the phrase…. “I don’t want it to leak!” I liked Justin’s personal install on his Chevelle with even higher pressure black mesh hoses. Together we chose to use the higher pressure hoses and AN fittings at the PS reservoir (rather than barbed fittings). We added the extra return connection to the reservoir rather than using a Tee fitting (one was included in the kit). Because of the custom install and our personal choices, we needed some different fittings than what came with the kit. So we saved (did not open) the purchased kit and Justin created one for me. Our custom hose/fitting set cost more $ than the kit's set.
 

·
Registered
Joined
·
3 Posts
This is a wonderfully thorough thread. Thanks. I am hopeful someone will add a few subjective comments as to the changes (improvements) noted after the install. Thanks again!
 

·
Premium Member
Joined
·
3,982 Posts
Discussion Starter #20 (Edited)
3 Month Follow Up

Three Month Follow Up To See If Goals Were Met.
I collected the info in this article as we started and completed the install. I don’t have a set of before and after comparative stopping distances to report. Therefore, what appears below are my personal experiences and observations.

GOAL 1: Produce improved power brake assist.
Definitely Improved.
Hydro boost creates more pressure to the brake cylinders/pistons than vacuum brakes. The truck stops almost instantaneously from 20 MPH. I really have not tried a panic stop. I did slow quickly from about 65 a couple times. Now they are strong enough to feel the slight pulling to one side. I no longer use both feet on the brake pedal.

GOAL 2: Produce consistent power brake assist.
Highly Consistent.
Prior to the change, I watched the vacuum/boost gauge more than all other gauges combined. Not to read boost, yet to see if enough vacuum was generated to have any assist the next time I applied the brakes. It took about six short trips to break that habit. I now check for boost, because I am less reluctant to pass a car/truck.

On the way to the shop to get the change made, I could not build enough noticeable vacuum for brake assist in the stop and go freeway traffic. Regular freeway or PCH drives caused totally unpredictable brake assist.

After the change, stop and go freeway as well as PCH traffic show no noticeable difference of pressure needed for repeatedly slowing/stopping.

I can’t tell if there would be any fade on an autocross track, yet feel it would be less than the loss from a vacuum booster.

GOAL 3: Stop prior to the rear bumper of the car ahead.
In addition to wanting to be safe, there were other factors encouraging the change to safer brakes.

Last fall, on the way home from Pomona Auto Swap Meet, my Honda was passed by a mild small block white 3rd gen. As I flashed him a “thumbs up”, I wondered what would need to change on mine to have brakes good enough for that drive. I remembered the phrase: “You need to be able to stop as fast as the vehicle in front of you”. Three miles down the road, the white El Camino now needed a new front clip. That was an item not on his list when he left the swap meet. I felt bad for the fellow, and decided to find out what would be needed to get close to stopping as fast as my light weight Honda. That is when Goal 3 was set.

Brake technology improved over 45 years. I think the Honda can out stop the truck today. However, I think the El Camino now stops as good as or better than it did in 1970. When I locate even better pads and shoes and have those installed, I think the truck will stop better than when new.

Since the brake upgrade occurred at the same time as the three point seat/shoulder belt upgrade, I could move forward with two changes:
• Now I ask an adult niece or nephew to ride with me to car shows. I don’t have kid seats.
• One nephew has now been added as an alternate driver on my AAA Collector’s Car Policy.

Let’s think back and remember in Driver’s Ed. class of about 1970. “Always leave a full car length between you and the car in front of you for each ten miles per hour.” Prior to the upgrade I had a different rule for the El Camino. Rather than car lengths, it was a semi-tractor with 53 foot long trailer for each ten MPH.

Now that we are much improved, I will leave the slow lane and pass as needed. With an original stock 45 year old suspension (shocks had been replaced), lots of small noises, I like the slow lane. However, I no longer need to be there to dive onto the shoulder because she will not stop.

What else?
This is not a cheap solution. For my low vacuum situation, this solution produced a more affordable and better end result than adding $3K to $4K in expensive large front and rear disk brakes. The first post lists other alternatives that should be considered before making a decision. If you arehaving braking problems, yet generating a lot of vacuum for your vacuum power assist, find out what is failing in your current system. Hydro boost does not magically fix other brake problems.

Would I Use Shear Performance in Costa Mesa Again?
I used them for the subsequent project to improve reliability of the truck’s starting system. I will use them again.

Over the River and Through the Woods
There is a winding country highway that goes from the Coast through the Cleveland National Forest up, over and then down a mountain into Lake Elsinore. I would now consider taking that trip.

If I do and you tailgate me through the shadows of the hundred year old oaks, don’t expect me to pull off into those loose gravel turnouts and chip the paint!
 
1 - 20 of 59 Posts
Top