completely new brake system = major problems

well i have a completely new brake system in my 54 chevy 3100 and am having major problems trying to bleed it.

the system is:

-new 7" power booster with corvette dual reservoir master
-front is 85 s10 new calipers, new stainless hoses, new pads
-rear is 88 ranger 10" drums, new wheel cylinders, hardware and shoes
-brand new 3/16 lines throughout the entire truck
-2lbs residual valve for the front and 10lbs for the rear
-no proportioning valve

the master was correctly bench bled prior to installation!
been checking for leaks but really hard to do when there is no pressure what so ever in the lines. i have one of those speed bleeder kits which hooks up to your air compressor and i let it run on one front caliper for about 20 min, went through roughly 3 large bottles of brake fluid and there is still lots of large air bubbles coming out. have tried everything from a buddy pumping the pedal to gravity bleeding still have way too much air in the lines. anyone have any tips or suggestions?! at this point i'm considering just taking it to a shop, and i haven't taken a car of mine to a shop in over 10 years. been messing with these brakes for 2 months now!!!!

note: on this first pic the line for the front brakes is hooked to the small reservoir on the master, i have since corrected this and the front line is now hooked to the larger rear reservoir

 

looks like the calipers are on the wrong sides. Bleeder needs to be on the top not the brake hose.This should fix your problem instantly.

 

I had a VERY frustrating experience with one of those Corvette style master cylinder setups. To make a long story short, I tried three different master cylinders before I got one that was sound. Mine had an intermittent failure syndrome after bleeding. I would have good pedal for a while and then at some arbitrary moment my pedal would go clear to the floor when applied. A couple of pumps and it was back up to the top.
Your brake system is really pretty basic and should be straight forward. My best guess is that your master is no good if you can’t get any pressure built up at all.

 

Man I missed that one! Pays to look at the pics.

 

tks for pointing that out forgot to mention i have also switched the calipers so the bleeders face up since that pic, although it helped alot as there is way more fluid coming out still cant bleed the damn things. the rear wheel cylinders are doing the same thing as a note.

could there be a large enough leak from a bad flare somewhere letting all that air INTO the lines?!

 

Your calipers are upside down (or on the wrong side of the car, take your pick).

With the bleeder down like that, you'll never get the air out.

Swap sides and try again, it should go much easier this second time 'round.

EDIT: You posted again while I was typing.

Are you sure the rear backing plates are on right side up? All the drums I've had apart have had the wheel cylinders at the bottom. Now, admittidly, I don't deal with drums much (out of choice), but the half dozen or so I've taken apart all had the wheel cylinders at the bottom of the backing plate. At any rate, just make sure those bleeders are at the high point of the cylinder.

I would think that any flare bad enough to let air in would let fluid out when under pressure. Do you have any leaks?

 

Come on guy read the posts he already figured that out the calipers were reversed and drums with the wheel cyl's on the bottom ?? Nope wrong answer.. One thing you might try is crack all the bleeders go drinking for a week then come back and tighten em up and see where you are.. Also check the rods in the booster to m/c make sure they arent too long or too short.
Dave

 

Another thing to try is to get a vacuum pump with a brake bleed kit. start at the right rear then work closer to the MC. Most of the time this works unless you have an air leak. Then this way helps you find it a lot quicker. Good luck!!!!!!!!!!!!!!!

 

JusJunk has a point ... if you have it all closed up and there is NO pressure at all, maybe the master cylinder/booster rod is too short.
If there is any pressure have you tried starting at the right rear cylinder and continuing forward till you've mde it all around?
I can't understand how there could be NO pressure ... and those rear drums look just like what I've seen, ie - wheel cylinder on the top.
Hmmm. I'll be watching this one.

 

What are you using for a proportioning valve? vettes had 4 wheel disc, so the flow to the rear is not the same and must be adjusted. I have the 1" vette master and an adjustable valve to the rear.

 

with the whole system closed the pedal travels right to the floor with no resistance. i've tried bleeding both sides of the rears with a hand va***n pump and the old buddy pumping the pedal system, same deal lots of large bubbles. i have yet to try it with the compressor driven va***n pump though.

as far as the rod for the booster/master you mean the internal one?! i bought them both as a combo together. and the internal rod that came with the kit seemed correct for the apllication. i do have adjustment on the rod that connects to the pedal ***embly and i have that adjusted out as to as soon as you press the pedal it pushes in the booster rod. should i adjust it out more?

tks allot for all the replies guys, these things been beating the **** outta me and i really apreciate the help!

 

there is an at home power bleeder, uses air pressure from the tire to push where the master cylinder cap goes, with extra fluid in it. you simply crack a bleeder until a stream shoots out. if its still not working, bad master.

and you need just a little slack in the pedal, don't go too far with the adjustment.

 

Try a prop valve, it will regulate the flow from the front to the rear, you can get one at www.cl***icperform.com they also have a great tech area!
John

 

I always used a mason jar filled with brake fluid and a buddy on the pedal to bleed lines - never had problems. Maybe those newfangled tools are overcomplicating things?

 

I know this will sound stupid but, did you have the brake drums on when you tried to bleed the brakes? Stupider things have happened

 

OK this might be a bit in LEFT FIELD, but what the heck.

When I did a similar conversion (except I used a proportioning valve) I had a heck of a time bleeding it. This is COMMON with all brand new components. With gi-normous amounts of air in the system it will be very difficult to bleed - especially if some of your lines have localized high spots for air to be trapped in. IF you don't get ALOT of pressure and or volume you end up just p***ing the fluid past the air bubble and never actually displace it - and therefore never actually bleed your system. So what to do??? Well for one thing try 'pre bleeding" your lines. I've done this with a big syringe. Power bleeders are the cats *** here, but if unavailable try the syringe.

If you're still plagued with issues, then I think the next thing to look at is the M/C itself. Take that ****er apart if you have to - if it was rebuilt in CHINA who knows what the hell those nitwits may have left out.
The other thing that confused me when I did this was the Corvette M/C itself. I bought one at the parts store that I asked for a "power brake" model. They brought me one that had a DEEP HOLE in the piston. I needed one with a shallow hole. (I thought they had their stock mixed up and went to another store who brought me the exact same thing a DEEP HOLE in the "power" version. Neither store had a "manual" one I could compare to so I just took it and swapped pistons at home. So you need to verify which one you have there - and while you're there adjust the little "pushrod" on the booster so that it is close to the piston - I set mine pretty darned close - like 1/32" clearance at most.

Which leads us to the next question: Can you look into the M/C and verify that the piston is in fact RETRACTING far enough??? You should see the piston go past the "port" as you stroke it.

There's always the chance the M/C is bad - but I'd rip it apart before I came to that conclusion.

 

lol yeah they were on.

one thing i'm doubting is my flares this was my first time flaring and after a bad experience with a harbour freight flaring tool and having to redo all the flares and some new lines i went ahead and borrowed a high end tool from a friend re-did everything from scratch and on the vice versus under the truck. but like i said i see no fluid leaks out so far, but i'm wondering if air is leaking in?!

as far as the prop valve i don't think it's needed in this case to get the brakes bled and working, but once the system is working if i see the rears locking up i'll put one in, if not all is well.

 

Not to be a **** but how did you bench bleed the master? Did you make some lines and run them into the reservoir or use those ****ty plugs?

 

My 2 cents - have a buddy come over and take a look at it. I know when I'm frustrated and sick of something a cooler head than mine can be a real help, especially when I'm just know I did a procedure right-cuz I've been known to be wrong hehe

 

the ****ty plugs i guess, but that thing was bled to perfection not even tiny little bubbles were in the lines, just perfect stream of fluid.



i'd love to have someone come over and look at it, but i know 10 times more about cars than anyone around me. thats why i made the thread i figured you guys could think of things i cant!

 

i'll def check to see if the rod is retracting all the way back and unbolt the master and check that the adjustment on the booster rod is correct.

my question is though.....since i'm using a compressor va***n bleeder system all i'm doing is pulling fluid from the master and not using it to pump the fluid so regardless if the master is bad or not i should be able to get all the air out the lines no?! and if not maybe the problem lies else where, i'm leaning towards my flares..

 

i see you keep talking about your flares and the wonder if they are ok..and you keep saying no fluid is coming out and wonder if air can get back in..if it isnt leaking fluid (that is supposed to be under pressure) out than i dont think air should get back in. Im leaning toward the master cyl. or the booster/ brake rod and master cyl. piston isues..

 

This may sound dumb, but make sure that the rear drums are adjusted properly, I/E they drag only slightly when you put the drum back on. Sometimes, if there is space between the drum and the shoes, you wont get any pedal until the shoes contact the inside of the drum. Also, like others have said, with a brand new system, it's going to take FOREVER to bleed all of the air out.

 

good point but at the same time i'm doubting my flares cause it's the only thing which was a first time for me, everything else from changing masters, bench bleeding, swaping new hard and soft lines, calipers, rebuilding drums i've done tons of times before.

 

If your pedal is going clear to the floor all of the time I'd still take a close look at the M/C. Take two short brake lines and crimp the ends off to make a couple of "dead ends". Disconnect the master from the rest of the system and attach these to the master cylinder. You should have a hard pedal. This will at least isolate your problem. Try reattaching the front and rear lines one at a time. You can eventually track this thing down.

 

Look at the post times jack***, he posted saying he'd already swapped them while I was typing out the post. That would be why there was the "EDIT:" at the bottom.

I also did not say that the backing plate was for sure the problem, I just said it was something to check. You'll also note I said I wasn't an expert on drum brakes.

This place is a wealth of knowledge, but sometimes you folks can be real *****s.

 

ya know what 50flathead has about the best advise to trouble shoot this right out of the gate..1st determine if the M/C is your problem than go from there...

 

Yes I am a ***** thank you and where did you see real drum brake cylinders on the bottom.. ?
Have a nice ****ing turkey day..
LOVE
Dave

 

Since you've had the m/c off the booster, did you see the "insert" that goes in on top of the piston in the m/c? When using a booster, you use a 'short' rod with a plug that takes up the space. With NO booster you leave the plug out and use a "long" rod to the pedal. It could have been left out at the vendor............ Most of the m/c are 'replacement' type that need this plug.

 

There are a number of different versions of the Corvette MC, make sure you have the right one. Some were meant for drum f/r, other disc f/drum r, others disc f/r.

I installed one years ago in a rockcrawling jeep, it was the wrong one and was messed up. I also had to fab a pushrod to make it work right.

Mine was 4 wheel disc, no prop valve, NO booster BTW. It locked up 40" tires like they were bicycle tires. It was a from a '68 vette. I am doubting you need a booster with that. Even with '68 MC's, there were different types.

If flares were the issue, fluid would be leaking out.