apie2546

Looking for some advice on shoddy brakes.. Posted about it before but I've made some updates over time.

Symptoms:
Far pedal travel
Need to pump to build decent pressure
Far travel will engage brake light, pushing pedal to floor again will reset it
Poor brake performance

What I've done:
New prop valve
New brake fluid and brake bleed
New prop valve
New mc cap

Any suggestions? Hell bent on not taking it to a place to fix it, but its become borderline dangerous, especially in rain.

Hoping its not the master cylinder ( all junkyard cars here have rear drum, I have ws6). But we will see. Any tests to check if the mc is bad?

Thanks!

MSgt Luttrell

It more than likely is the master cylinder, but I'd change the brake hoses too, it will help a lot, as old worn out hoses deteriorate internally and can actually baloon causeing a spoungy peddal and uneven pressures on your front brakes.

apie2546

The brake hoses looked pretty well kempt when I bled them. Almost new. I will look a little deeper when this bad weather stops! Lol.

Would a master cylinder from a rear drum bird work on mine? Also any manuals on replacing it? Never done one on my own

MSgt Luttrell

You can do a part number search on autozone's site and see if the part numbers are the same; if they are the same, they are interchangeable. That said, if the donor car has sat for a long period of time, I'd avoid using the master cylinder from that car.

Changing it is pretty straight forward, a good bench bleed before installing it will save you a lot of bleeding; you will still need to do a regular brake bleed after the install. The bench bleed eliminates you pushing a LOT of air into the system and increasing the time it will take to get a good bleed of the system. Here are a couple of 'how too videos on the subject; get back with us if you run into trouble or have anymore questions.

Bench bleeding a master cylinder........

Changing the Master Cylinder......

apie2546

I appreciate that! That was a very helpful video. I couldn't find one for a thirdgen, glad you did! Looks pretty straight forward and easy. Looks a lot easier (and way cheaper than other vehicles).

I plan on going to auto zone to check the part numbers tonight, and if they're the same, I'll probably order one from JC Whitney or summit. Junkyard ones are too gone and not worth doing the job twice if the new one breaks.

I'll be sure to post back once I get it done and if it helps with braking performance!

Damon

Rear drum brakes doesn't us the same MC as 4 wheel disc. Might looks the same, but it's not.

ex-x-fire

Pinch off all the brake hoses, is the pedal high & firm. Release each one (at a time) till you find the one that causes the low pedal.

apie2546

Sounds good, looks like I'll hunt down a ws6 master cylinder

Ex - that's a great easy thing to do. L try that out tomorrow morning. I assume if all brake lines are clamped but the pedal still sinks its the mc?

JamesC

iTrader: (5)

Here's an interesting take from GM on drum and disc masters (you may be surprised at their advice):

https://www.thirdgen.org/forums/susp...fferences.html

JamesC

apie2546

Pretty interesting read, from what I can tell I have j65 brakes, not the better mc though. Which I guess is fine, I'm just looking to stop without pedal pumping and rear ending lol.

As an update, new mc is in the garage and I'm getting it done today along with bleed. I was not able to test the brake hose hoses, they do look pretty new (clip is still shiny). Benefits of buying from a car guy. If it is still spongy after, well the wheels will already be off for more trouble shooting! Let's hope they put me through the windshield

apie2546

Got to it today, master cylinder made no change, but I got to looking and the rear pads were loose. I remember my e brake hasn't worked since I bought it. I rigged it up to tighten it and I adjusted the rear calipers, now it works like new!

Anyone know where I can get the entire p brake assembly? No lever, but everything from the lever, back for four wheel disc