Narrowing down brake issues...HELP.

[levicah]

74' Plymouth satellite, 318, original front disk/rear drum. I dont have a vacuum pump to properly test my booster, suggestions? and here are my symptoms:
1. Got a whoosh or air hiss at the brake pedal. 2. Master cylinder reservoirs pressurizing when bleeding brakes. 3. At first, rear brakes responded to pumping pedal and bleeding, however in a minute, it looses pressure, pedal goes to floor. 4. When bleeding the front, no lasting pressure happens, pumping the pedal literally feels like pushing fluid back and forth. 5. No obvious fluid leaks anywhere, except m/c lid, yet pedal spongy no matter how much bleeding. No obvious place sucking in air. 6. I noticed passenger front rotor had a moist film of fluid on the face...meaning no pad contact.

So, all these components. I aint rich. Dont know where to start. Already bought The wrong proportioning valve. Any input will help.

 

[davek]

is the seal good on the booster,meaning the o ring that hooks to intake? If the car is running do you hear a hiss next to the booster?Put soap around o ring and see if you get bubbles.

 

[Ron H]

Checking your boost as said is a good check and getting a vac gauge to do a couple suggested checks would be good if you don't find any visible boost leakage. Not sure what you're finding with your #6 note that sounds suspect. What's making it 'moist'? Could be a defect piston seal and/or pitted cylinder bore. When you say MC is pressurizing the conventional bleed process is leaving the lid off but with assurance you keep reservoir full enough so as to not have air enter into the MC when doing bleeding as ya likely know. Not knowing what shape your brake system is in you'd want to check to see if MC is functioning properly...no ills there.

 

[Moparnocar]

So, car running, and you pump the brakes 3/4 timed after sitting for a few minutes, what happens?

1. Pedals soft, then gets hard
2. Pedal is always soft, no matter what, or pedal goes to floor?
3. Pedal is normal, then drops after some pumping

Do you have one of those minivac hand bleeder's? They are like $40 and come in handy

 

[BB BELLA]

if you slowly push pedal and it goes to floor but you stab the pedal it firms up the m/c is bad!

 

[Evan Frucht]

My guess is that you need a correct proportioning valve first of all. I'm not sure what one that is but you say you got the wrong one. It could be a bad wheel cylinder or the brake lines are damaged or corroded throughout. Based on what you say.

Could also likely be the master... I had one go bad on me. If the pedal is firm sometimes but also randomly will go to floor and not work that could definately be the master. The seals that hold the pressure do just fail on you, but can also act weird and work intermittently. If the booster was bad I would think you might have a problem where the pedal stays to floor and doesnt return correctly after your press it or something like that. I'm sure many other weird things can happen but that's just from my experience.

 

[Evan Frucht]

Do you know the history on the brake system. Is it all actually original or just stock?

Have any of the brake parts been replaced that you know of?

 

[levicah]

Thanks everyone! So, the sound of air "whooshing" behind the pedal is of no concern? They want 190.00 and 2 weeks to rebuild the booster and M.C. I cant seem to find a vac pump for rent. Yeah, fluid will shoot up and out of the M.C. when bleeding, so I assume the MC piston seals are not isolating the reservoirs properly. Yeah, item #6 the passenger front piston must be leaking, but wouldn't explain everything. I will go over everything later today. I guess the booster rebuild is bumming my trip, because I cant rule it out w/out a vac. pump.

 

[Evan Frucht]

The "whooshing" air hiss sound is likely the booster going bad but its sounds like you have a combination of other failing parts too. If it's been years since the booster has been rebuilt and if you dont know the last time the MC was changed then I would recomend a complete overhaul on the brake system. I would check the brake lines and determine if they are corroded. They can corrode from the inside out. If those are questionable I would get a new set of stainless steel brake lines, all new wheel cylinders, brand new master cylinder, and then send the booster out to get rebuilt by Booster Dewey. He did a great job on mine. 190 is as cheap as you will get on the booster rebuild, maybe you could find a local shop who would simply replace 1 or 2 bad parts in it but I think you want it rebuilt.

I did that to my car recently. My brake system worked when I bought the car but it was all basically original and when the first wheel cylinder started to leak I lost trust in the whole system...

Wasn't hard to install everything. Just took a few hours and some patience. It was a few hundred bucks in total but well worth it to have worry free brakes.

Someone will know what proportioning valve you need.

 

[levicah]

Do you know the history on the brake system. Is it all actually original or just stock?

Have any of the brake parts been replaced that you know of?

Pretty sure all is original. This all started with the rear system doing all the work, inability to bleed the front...until I pulled the plunger pin on the Proportioning valve. Once the p valve was "re centered", I realized the front pistons havent been working for years...passenger front line was completely plugged and the driver side piston took lots of force to compress. So, just writing this crap out is helping me visualize what must be done...M.C. and 2 front pistons so far, but the booster has me stumped. I also did all the bleeding with the car off. Now, pumping the brakes just moves fluid back and forth.

 

[Evan Frucht]

If all original it probabaly has bad seals and corrosion throughout. I would reccomend replacing all wheel cylinders and MC and rebuilding booster at the very least. It sounds like a lot but it's honestly not too expensive and at least not overpriced. You can get the wheel cylinders and master from rockauto or ebay for cheap, about $100 total for all of it. My booster was $225 shipped to have rebuilt, I think my brake line set was about $200. A new proportioning valve and other fitting you may need will probabaly be about $50 bucks total. I got some new drums all around as well because they were so cheap. You could also take yours to a shop to resurface them on a brake lathe, usually that's 10-15 bucks if you can find someone who does it.

It took me a weekend to install all of it after I removed the old brake system and cleaned everything up, backing plates etc...

Get the part number for the parts you need on rockauto and then shop around on Ebay and Google using that part number and look for the lowest price. The premium wheel cylinders you should pay only 15-20 each at most. 40 maybe for the master

 

[Ron H]

There can be many gremlins in the braking system as posted as you get a view of how the entire system works. I have had an issue driving me bonkers I’ve yet to nail down I’ve posted about with my disk brake conversion that inserts yet more gremlins. It starts with ruling out the critters piece by piece. If the system is old then you get into what’s been posted about defects due to an old system that breaks down due to age. The rubber lines may be shot if they’re old, they could be collapsing or ballooning as you press the pedal. A bud found this to be his problem. The rear block on the diff could be gummed up needing cleaning or replacement. As you mention one front caliper isn’t responding to braking pressure, this indicates one very distinct problem. The slide bolts may be seized or the piston. If it’s an old system these are things to check out. A simple boost check aside from the vac gauge check, is to charge the brakes running the engine then shut off and remove the vac line form the boost…does it hiss when removing the line? The check valve on the line is another check. You can suck it open but not blow through it. Check the fluid, does it look clean or is it gummy looking? Disconnect the MC from the boost and see how the pedal reacts. Run the engine and make this check. If you find good bleed from the bleed process this indicates the cylinders are functioning. Have a helper press the pedal as you look at the caliper action as you may find a seize up from this look. As also posted, there are checks to see if the MC is the culprit.

 

[Builderguy]

The valve for the 1973 satellite is 3642 233 from a 1973 Mopar parts book. I know your's is a 1974 but I can't find that info just yet. Could well be the same (see below) but I will keep looking for the 1974 number.

Mopar Disc Brake Proportioning Valve & Metering Valve for Disc Drum

• Oe style mopar disc drum proportioning valve / distribution block
• This is a metering block mounted to a proportioning valve & will fit the following applications:
• Fits a,b,c and e bodies from 1960-74 with disc front & drum rear.

 

[MoparLeo]

Safety first, always. The most important system on your car is your brakes. I am assuming that this is your second car and not the primary dd. So Sounds like a complete rebuild of the brake system is in order. If you can get your car to a brake shop, pay their fee if any for a complete brake inspection and get a written estimate. This will be your shopping list when you get home. Brake it up into little pieces as your budget allows and don't cut corners. Do it right and do it once. Get a service manual for your car. You can download one online for free and study up on the brake section. Read,read,read and learn all you can. It is best to have experienced help and you don't need expensive tools. You can rent many from the parts houses when you buy parts from them. Make it safe for you and every one else on the road.

 

[levicah]

[QUOTE= "Get a service manual for your car. You can download one online for free and study up on the brake section."

for free? where can I find this?

 

[levicah]

Ok, booster is out for 2 weeks getting rebuilt as are the front calipers and master cylinder. I bought a aftermarket proportioning valve that I am returning, I would rather spend more so that everything hooks back up instead of bending new tubing.

Is there any benefit to blowing the lines out with compressed air while nothing is hooked up? or should I just push new fluid through everything while bleeding? I'm still hazy on bleeding sequence and when and I fiddle with the plunger on the proportioning valve...I get what the plunger does, but I dont understand when or why I would manually operate it. Ok. back to the "when" and bleeding sequence: I bleed the back system, so I cant then bleed the front until I "equalize" the pressures by recentering the P.valve piston. Does this sound right? A lot of folks say they just bleed furthest to the closest, without having to mess with the p valve. what does that mean? a p. valve isolates the system that drops in pressure correct?

 

[Evan Frucht]

Ok, booster is out for 2 weeks getting rebuilt as are the front calipers and master cylinder. I bought a aftermarket proportioning valve that I am returning, I would rather spend more so that everything hooks back up instead of bending new tubing.

Is there any benefit to blowing the lines out with compressed air while nothing is hooked up? or should I just push new fluid through everything while bleeding? I'm still hazy on bleeding sequence and when and I fiddle with the plunger on the proportioning valve...I get what the plunger does, but I dont understand when or why I would manually operate it. Ok. back to the "when" and bleeding sequence: I bleed the back system, so I cant then bleed the front until I "equalize" the pressures by recentering the P.valve piston. Does this sound right? A lot of folks say they just bleed furthest to the closest, without having to mess with the p valve. what does that mean? a p. valve isolates the system that drops in pressure correct?

Good call on the booster rebuild.

I dont think blowing out the old lines will do much but if it makes you feel better. I might avoid doing that in fear I may end up making matters worse
blowing some debri into the lines. The bleeding will clear it out just dont rush it it will take a while to get all the old fluid worked out of there.

You dont have to bend your own btw, they sell full kits thats are pretty cheap from what I remember. I got mine from inlinetube.com. Id reccomened going to stainless lines too. The originals are regular steel and rust.

 

[BB BELLA]

It's been quite a while since i played with mopar brakes and troubleshooting. just wondering if the the mopar gurus know if the residual valve is in the master or proportioning valve. OP states that rear bleeding firms up and then goes soft. if the residual was bad and the brakes weren't adjusted tight this would happen,also stating the m/c is pressurizing would lead me to believe the rear springs are pushing fluid back to m/c again pointing to residual valve .my.02

 

[levicah]

What constitutes the "core" of my front caliper? The reason I ask: The carriage bracket (for lack of proper term) is held to the rotor by 2 - 3/4" bolts, mine are not budging since 1974. Does the part store really want the whole mama jamma for a core exchange? I would hate to snap those off.

 

[coloradodave]

What constitutes the "core" of my front caliper? The reason I ask: The carriage bracket (for lack of proper term) is held to the rotor by 2 - 3/4" bolts, mine are not budging since 1974. Does the part store really want the whole mama jamma for a core exchange? I would hate to snap those off.

No, the core is just the caliper itself....