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Discussion Starter #1
BRAKES SUCK! ............................................................................................I CAN'T GET THE BRAKES TO WORK ON MY 68 EL CAMINO. I TRIED, PAID 2 MECHANICS AND THEY WORK LIKE CRAP. CHANGED everything new but the proportioning valve. Hard petal no stopping. Everyone claims that it's not the proportioning valve.
 

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Did you replace the brake lines and hoses? New master cylinder and booster?

Rick

Sent from my SM-G965U using Tapatalk
 

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welcome Mark
good pads on front [70% of braking ] make a BIG difference, over the cheap ones..

was it a kit or what, what started all this ??
got pics or part numbers ??
everything new don't mean it works together..
 

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Discussion Starter #8
welcome Mark
good pads on front [70% of braking ] make a BIG difference, over the cheap ones..

was it a kit or what, what started all this ??
got pics or part numbers ??
everything new don't mean it works together..
No
Did you replace the brake lines and hoses? New master cylinder and booster?

Rick

Sent from my SM-G965U using Tapatalk
Everything new but valve
I replaced everything but the valve, to factory parts.
 

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Discussion Starter #10
welcome Mark
good pads on front [70% of braking ] make a BIG difference, over the cheap ones..

was it a kit or what, what started all this ??
got pics or part numbers ??
everything new don't mean it works together..
Don't have that info. It soft brakes when I bought it.
 

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hi Mark! A lot of times things get overlooked and now that you've had TWO mechanics try to fix it, that means potential problems they may have introduced w/o meaning to. I've had problems like this where I had to present it to someone else and they said "Yes, BUT!... did you check this or do the steps in this particular order?" It usually boiled down to me being forgetful or ignorant and we were able to solve the problem from there. so please read the questions below and answer each one. Thanks!

so just to clarify, you replaced EVERYTHING with factory parts except the proportioning valve?
and you had soft brakes before?
and you have soft brakes now/still?

so you replaced:
-calipers
-caliper brake hoses
-steel brake lines (including the ones attached to the rear axle)
-master cylinder
-booster
-DOT 3 brake fluid, from a fresh unopened can

what engine do you have and what kind of cam does it have in it?
has any adjustment been made on the brake pedal in regards to how it bolts to the booster?
as Old Bear asked, what is your vacuum reading and how did you measure it?

Hoping we can get a resolution for you.
 

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Discussion Starter #12
Yes on all parts and fluid. It had soft brakes yo start. I was talked into all new parts but por. Valve and canister. Brakes are hard now. Cam? Old and new hook up, yes it has been suggested and on my list. Vacuum check is my first priority.
I was to tackle this project this weekend and gave the days up for a short vacation. My truck trailer lost brakes and is now mt priority, need if for work and its 95 degrees out which is a killer. Ill get back to you after clearing trailer issues. Thanks.
 

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wait, canister? what canister? you said Everything was changed except proportioning valve, and now you're saying everything except "por. Valve and canister "
 

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Discussion Starter #14 (Edited)
I didn't think the canister had anything to do with the brakes. I had two garages not mention anything about the can. I was just reading up on it and a member Greg posted and told me to give him a call and I did. I talked to him or about 20 min., It was great he gave me his number and talk me thru his issues, which were identical problems The canister is called a couple things by name "vapor vacuum canister, vapor, vapor gas canister, vacuum canister......" I was not aware that this was part of the brakes. Quite a few mentioned the vacuum of the engine, which is driving in that direction.
The issue now is finding one that fits or a replacement. Greg mentioned Summit racing, contacted them and they had about 8 different models, which do I choose?
 

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Mark. From your avatar, it looks like we are talking about a 1970 to 1972 El Camino.
Edit: I see now that this is a 1968.
You mentioned a proportioning valve, stock 1968-70 El Camino did not come with a proportioning valve.
They use distribution blocks. This acts as a pressure differential switch. 1970 has a hold off valve.
The 71-72 appear to use combination valves (not really proportioning valves).
From ARK68SS about distribution blocks
"It's purpose is to activate the BRAKE lamp in the dash if there is a pressure loss failure in the brake system. There is a piston inside the switch that is centered by springs on either side. The piston will stay centered under braking when there is equal pressure on both sides from the front and rear brakes. If there is a leak in one of the circuits, when the difference in pressure reaches 150~250 psi, the piston moves and grounds the BRAKE light. "

We are not sure if this vehicle even has power brakes, drums or disk brakes in front or if the brake system has been modified from stock.
Maybe it would be good to start by updating us on that information.

1968-72: With stock power disc front brakes, the brake assist will be provided by a brake booster that holds (stores) vacuum to assist with power brakes.
As JJLT1 mentions, there is a check valve that attaches to the vacuum booster to keep vacuum available.
If it is not working correctly, vacuum will not be created in the brake booster reservoir.
If the hose going to the check valve has cracks or not sealed well, the vacuum will pull air into the hose and not have enough strength to pull a vacuum into the booster reservoir.
It sometimes happens that a new member finds out (as I did when I bought my truck) that their modified engine is running a cam or other modifications that prevent the engine from creating enough vacuum to keep the brake booster vacuum reservoir at a high enough level to assist the brakes.
Brake systems vary, yet knowing how much vacuum your engine produces and whether that is sucking a vacuum into the brake reservoir can help to explain if the booster should be working well.
 

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If we guess correctly that you have vacuum assisted power brakes, use the 3 step procedure in this CPP brake trouble shooting guide to test your power brake booster.
Note that it does not account for low engine vacuum.
 

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68 from factory came with drum brakes, sounds like someone did partial upgrade?
I had a 69 with drum brakes, found info from Gm that front disc brakes were introduced mid production year, so swapped all parts over with late model 69 parts, from spindles outward.
had same problem hard pedal - yet hard to stop switched master cylinder for later model to solve.
drum master has same size cavity for front & back, disc uses less volume, therefore more pressure than drum.
i switched brake pedal also, but cannot remember if it was due to difference in leverages or to match linkage or why..
good luck!
 
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