Brakes on my 87 El Camino
 

I have an original low mileage 87 el camino - 20K miles.

pads, rotors, and all the brake system is orig to the car. I feel like the brakes are spongey - like if i wanted to, I cannot LOCK them up if needed. It will stop, but to a slow roll, not lock up.

I bled the system and flushed out the fluid and installed new fluid. No real change - so im trying to figure out where the issue may be - booster, master, calipers and rear wheel cylinders need cleaned out and redone. Not sure best way to separate the diagnostics to pin point he issue, or am I at a trail and error?

Any advise? I have no leaks in the system, just a soft feel to the brake pressure.

thanks in advance.

When you bled the system did you get a good stream of fluid? If the proportioning valve has failed or is not working properly you may not be getting enough fluid to the front or rear.

yep we had an issue with the rear - had to force some fluid thru when we opened the bleeder - i was using a suction tool to bleed the brakers thru the calipers. at first nothing then applied some brake pressure and a big stream came out........i can't say it was nice solid stream.......maybe look into the prop valve? R&R clean, rebuild - they rebuildable?

I think the 1987's were similar/same to the earlier 1970's GM cast iron units and yes they are rebuildable by any of the typical places for calipers/wheel cylinders. The valve may be stuck due to rusty fluid/varnishing and not allowing enough fluid through.

ok will look into this today! appreciate the thoughts and guidance.

----Along with what Jake said, I would replace the pads. They may be glazed and certainly are old. Possibly have the rotors fly cut to give the new pads a good brake in surface.....Bill S

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All above plus pull frt. calipers and service slide systems also remove drums and confirm rear wheel cylinders Ok both directions + adjusters free and wound out as far as possible but you can still get drums on/off.
Next, elevate rear and bleed system, RR first on to LR and RF w/ LF last also if weak pressure bleeding, consider flex lines may be internally collapsed whether they look good externally including rear flex if low/no pressure @ wh. cyls.
Best of luck!
:beers:
~ Pete

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This is great advise!! :biggthumpup: - Bill W

Rebuild kits. https://www.musclecarresearch.com/

Sounds like a good brake overhaul would be best approach......one can spend alot of time on one item or another, hoping to identify the issue etc.

Comprehensive brake overall might be in order - new rubber lines all the way around - new proportioning valve, pull and rebuild all brake calipers - fit and rears......

flush and clean system - see what we have.

i was trying to avail this level of effort, but all the points / suggestions above drive me to think this is the best approach. related to the booster and master cylinder - maybe a rebuild of the master is in order - i have good boost from the booster - so that will be the only think i dont touch.

sounds??????????

All of the above and my 2 cents are cups in master are allowing fluid to bypass internally and won't necessarily leak externally, but cause the spongy feel. Also, the rear flex hose sounds like it is collapsed, causing the restricted flow and will expand under pressure, again can cause spongy pedal.

----Forgot about the flex lines!....Bill S

I would suggest before you do anything, go buy (2) new wheel cylinders for $20.00 each from a NAPA store and replace those first. If I remember correctly, an 1987 El Camino had 3/4" wheel cylinders and they were known for the pistons sticking internally, quite common for causing a car to not being able to lock up the brakes in a panic stop situation. A very cheap start before you do all that proportioning valve & caliper stuff.

Bill

Understood - and thinking thru this - im getting more comfortable that i dont have solid rear brakes....so from that perspective - prop valve back may be the issue. Easy enough to pop in 2 new wheel cylinders in the rear and see what happens.

On this topic - i have seen the flexible brake lines collapse on the inside on a variety of cars - is there any rule of thumb when it is wise to change out the flexible lines?

You're going to have to bleed the rears after the wheel cylinder replacement, NOW is the time to change that hose too. :beers:

yes why not at that time - Ill order up some parts and plan the work next weekend.

Get the GOOD cylinders from NAPA that Bill mentioned. Don't order some chinese crap off amazon or cpp. They have the brake hose too.

I personally would start with just the brake hoses. Yes, it will require another bleeding if it’s not the issue but in my experience it is the place to
start.

Jason

With a 20,000 mile car? I've seen hoses cause a wheel to lock up and not release when they deteriorate, but not cause a car to not panic stop, that's normally caused by a stuck caliper or wheel cylinder. I still bet it's the wheel cylinders. But once again, "I'm just Sayin" Bill

OK, well parts ordered - say next weekend project and see what happens.

Im going to replace the wheel cylinders rear, rear rubber hose and for i also purchased a set of across the axle brake lines - in the event we have issues getting the other lines off easily, ill have a backup plan immediately.

Appreciate all the advice guys!

Definitely what Bill says here, while you've got it in the air check and free up the front caliper slides to be sure the calipers are freely centering on the rotors. - Bill W

If you don't have them already get a GOOD set of line wrenches and for that year, they may well be metric. Be patient with the line nuts and work the wrench slowly but firmly. Those nuts round off all too easily.

And remember, if you use any heat on them, be careful because the fluid inside the hoses can cause the hoses to explode. Good luck, and stay tuned with your progress. Bill

I would replace the rubber line that feeds the rears at the T fitting (typically is one) at the rear axle area.

OK, so I replaced each rear wheel cylinder, both brake lines across the rear axle, the flex line at the rear end, adjust the drum to shoe clearance and rebleed the brakes.

We have way better brakes - but it does not lock up like i believe it should. Maybe im expecting too much - or at this point maybe i have some front brake issues. Clearly the car nose dives with brake pressure, the proportioning valve seems to be working well - based on the bleeding process.

I'll drive it for a week of so and see if i get a different feel. I did notice that i had some small brake fluid residue on the passenger side brake cylinder.

So will give it a few miles and see if im happy enough. Swapping out the parts was very inexpensive way to go.

BTW - Old flexible hose seemed to be in good shape . Lets see....

Thank you all for the comments and direction.

A couple of things to check:
After a few test stops, does it start to pull to one side or dogleg?
Have you checked the brake temps with an IR temp gun?
You mentioned that you had to force fluid out for the rears? You probably have a failed rear brake hose at the axle. Those internally fail. I would replace.
How long has it been sitting before you started this project?

Well that's a good thing. Just remember the rear shoes and drums have not been applying correctly for a long tine due to the frozen wheel cylinders so I would start by resurfacing the drums to deglaze them and replace the rear shoe set and spring / hardware kit (cheap fix). That is a better fix than re-using the old, glazed shoes.

Once again as far as the brake hose issue goes, I have only seen an internally failed hose cause a brake to not release the fluid or at minimum restrict the flow causing a pull to one side or the other. Remember it's only original once. Look at what an original pair of red striped brake hoses for a 1969 Camaro are going for today. Who knows, your 20,000 mile 1987 El Camino could be a future 1969 Camaro as far as collectability down the road.

One has to be methodical with diagnosing issues with vehicles. Like Snap On tools moto was back in the day "TEST, DON'T GUESS"

Bill

answer to the questions above:
1. no pulling what so ever - nice and straight
2. did not check brake temps
3. replaced all the lines (1 hose with t fitting and the 2 metal lines) + wheel cylinders
4. its an 87 and has 20K orig miles on it - so obviously sparingly driven prior to me. i put 300 miles in this yr.

BB Bill - agree with you, i think I'll go ahead and order up some new shoes and hardware kit and have the drums resurfaced. At this point everything has been refurbished on the rear section eliminating this before looking at the front stuff.

----Wow, that's a great looking El Camino! Makes me wish I had never sold my 86 as I really liked it. Proir owner to me kindly installed a ZZ3 in it, so it delt with the one thing I have never much cared for, lack of power.

thank you...i looked for a yr before buying these wheels - and moved up from the 14 inch stock wheels to these 17 inch. I worried it would be too big a wheel, but not.