ProblemsSolved2

Just rebuilt my iron calipers for the rear, but they will not compress fully. It seems like only the pad on the piston side is contacting but the outer pad is not touching. Very poor braking is resulting and i can turn the tire while pressing the brakes. The e brake is also nearly useless and have pulled it MANY times to adjusting them with no luck.

ProblemsSolved2

hey are the j65 if I rember right. delco marine?

sofakingdom

iTrader: (1)

Yes, J65 is the RPO for disc brakes.

Yes, Delco-Moraine is the division formerly of GM, now of Delphi, that designed that system. (a piece of Dayton Engineering Laboratory Co., named after a facility including a GM assembly plant in Moraine OH, a suburb of Dayton OH)

Sounds like you might need to pull the parking brake MANY more times. Not sure myself how much it adjusts each time, or even, if there has to be some tension built up in the thing before it will ratch the ratchet thing in there; instead, might have to pop the calipers back off and adjust em out somewhere close by hand first, before the "automatic" system will be able to start doing its job.

ProblemsSolved2

You seem like a man with the know on this. How might I go on adjusting these calipers? I read previously that a wrench can be taken over the threads where the e brake sits ( once removed) and a bolt over the wrench to hold it down. It can then be adjusted this way? if that makes any sense?

sofakingdom

iTrader: (1)

That, I'm sorry, I do not know. I know about the tool for adjusting them the other way (out, to spread them, so new thicker pads will fit), but I don't remember how to adjust them up to take up the slack if the above adjustment went too far. It's been so long since I last saw them that I can't recall their details.

gearheadotaku

iTrader: (1)

I adjusted mine by removing the e-brake lever and turning the shaft. Be careful, the shaft must be held "out" or it will just thread into the caliper.

daferris

iTrader: (8)

Apply the service brakes ( brake pedal) firmly ( at least 50 lbs pressure with engine running for the power boaster to work). Apply parking brake at least 3 times hard pull. Let off brake pedal THEN let off parking brake. Might have to repeat a few times. It does work however. Then use parking brake every time you park. They will work big time better

ProblemsSolved2

I appreciate all the help! I got them adjusted and working. Yet I have another problem now. My brake petal is very soft. Occasionally it stiffens for a moment but I am nearly to the floor at every intersection. any ideas? would air cause this to? I've bled the system several times..

sofakingdom

iTrader: (1)

Yes air can cause that.

Main source for that problem is usually letting the master cyl run dry while working on something at the wheels. Because of the angle the cyl is mounted at in these cars, the fitting for the line is NOT at the highest point of the cyl; therefore once the air gets in there, it is for all practical purposes IMPOSSIBLE to remove by bleeding. You can bleed 50 gallons of fluid through the system and the air will stay RIGHT WHERE IT IS, unaffected in the slightest.

If that was allowed to happen to your car, you need to remove the MC and "bench bleed" it. This consists of: clamp it in a vise, level; install plastic fittings and tubes to take the output that would go toward the wheels when installed, and dump the fluid back in the reservoir; pump it until air quits coming out through the lines and bubbling up from the inlet holes in the bottom of the reservoir; put it back on the car with the plastic lines still installed; remove the plastic lines one at a time and as quickly as possible hook the car's lines back up; then bleed the whole system completely again, making sure not to let the MC run dry again.

ProblemsSolved2

but this is strange. the brakes will be to the floor when im coming to a slow stop from a low speed. but as I stop at a higher speed the brakes become much more responsive. the inconsistency is making it difficult to identify the problem.

sofakingdom

iTrader: (1)

Did bench bleeding help it out?

Bob88GTA

iTrader: (2)

"If that was allowed to happen to your car, you need to remove the MC and "bench bleed" it. This consists of: clamp it in a vise, level; install plastic fittings and tubes to take the output that would go toward the wheels when installed, and dump the fluid back in the reservoir; pump it until air quits coming out through the lines and bubbling up from the inlet holes in the bottom of the reservoir; put it back on the car with the plastic lines still installed; remove the plastic lines one at a time and as quickly as possible hook the car's lines back up; then bleed the whole system completely again, making sure not to let the MC run dry again."

I think I did just that very same thing! Thanks Sofa for solving MY issue. I left it go dry while bleeding mine after total brake system overhaul. I feel so stupid now. And yes, 50 gallons, didn't help!

sofakingdom

iTrader: (1)

Please don't do that!!! You're not "stupid", just, learning.

The mark of intelligence is, you just realized you learned something you didn't know, and you're smart enough to admit it.

Not knowing stuff is OK: we're all born that way. There's no shame in not already knowing everything there is to know. Not learning stuff when it's spoon-fed to you... now THAT'S a different matter.

Glad to be able to pass along my hard-won knowledge (from back before Algore invented the Interwebz) that it took me about a half-dozen brake jobs to learn THE HARD WAY, that now, smart people can learn by just reading what I type if they choose. I SURE wish such a thing as bulletin boards had existed back in my coming-up daze. Some of these young guyz just have NO IDEA how tuff it was for us OLD GUYZ to get better at this back in the day.

RED85TPI

Quick Question....

Why can't you "bench bleed" the master cylinder while its on the brake booster?

It seems to me that you could hook up the bench bleed plastic lines (as you would while on a vise) but use the brake booster (brake pedal) while the engine is running and pump the brakes?..?.. the piston from the brake booster pushes in the master cylinder just the same as a screw driver on a vise doesn't it?

Why would this not work?

Thanks...

sofakingdom

iTrader: (1)

Which letter of which word requires further explanation?

RED85TPI

Ok, after reading the quote again, I understand... It is simply the angle to which the master cylinder is mounted onto the brake booster that prevents bleeding it while mounted. So, you could in theory, just jack up the back of the car to make the cylinder level if someone didn't want to disassemble the system.


Thanks for clearing that up!

sofakingdom

iTrader: (1)

In theory, that's true... unfortunately, in REALITY, the back of the car would have to be about 4 - 5 feet above the front, to tilt the MC all the way to level. So yeah, if you've got a jack like that...