brakes giving me a headache!

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SirDan

SirDan

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so i put new calipers new wheel cylinders and new brake lines on (except the one that goes behind the engine but it doesent leak) and i cant get a firm pedal for the life of me. im thinking its possibly the master cylinder but i really dont know at this point. ive bled and bled and bled. ive bled the master cylinder too. any help would be great.
 
How are you bleeding? Pedal pump? Gravity bleed? Vacuum? Are the bleeders on the calipers at the top or bottom? (Sorry, I know, it's pretty basic, but I have to ask..) Are all the fittings tight under pressure?
 
You can isolate the master cylinder by clamping off the 3 brake hoses at the same time. You can use vise grips, but be sure to use a rag or similar in the jaws so you don't hurt the hoses.

If the brake pedal is high and firm while hoses are clamped off, the master is good. Bleed some more?? Brakes can be a pain sometimes....
 
gotcha...use the vise grip method above. If the pedal is high and tight then start unclamping one at time, checking the pedal after you unclamp each one. If the pedal drops, that's where your air is.
 
Is the right caliper on the right and left,left . I had volare brakes on a gtx and you would think the bleeder screw was at the top but not quite. I had them switched side to side.
 
6pk2goDemon said:
You can isolate the master cylinder by clamping off the 3 brake hoses at the same time. You can use vise grips, but be sure to use a rag or similar in the jaws so you don't hurt the hoses.

If the brake pedal is high and firm while hoses are clamped off, the master is good. Bleed some more?? Brakes can be a pain sometimes....
Click to expand...

im going to assume you mean the rubber lines. perhaps tommorow ill give that a shot. thanks for the tip.
 
I am having the same issue. I am going to use the vise grip on the rear line to see if that helps. I can't on the fron because they are Stainless. Has any one had issues with the adj prop holding air? Do I have to open it all the way when bleeding? The weird thing is I have no leaks. The fluid has not gone down.
 
siuauto said:
I am having the same issue. I am going to use the vise grip on the rear line to see if that helps. I can't on the fron because they are Stainless. Has any one had issues with the adj prop holding air? Do I have to open it all the way when bleeding? The weird thing is I have no leaks. The fluid has not gone down.
Click to expand...

I've had the prop valve stick and have the pedal feel like crap before. For those who haven't made the swap to ss, use the visegrip method to isolate where the air is, then take that line off and have someone push the pedal. You need to be watching the line. (Yeah, you'll get more air, but you're bleeding anyway..) If nothing comes out, then there's a problem. I've taken the prop valve apart, cleaned the hell out of 'em and put 'em back together. (**WARNING** not for the faint of heart!) Sometimes lightly tapping 'em with a hammer can unstick 'em, but that's a temporary fix at best. But it would help isolate in diagnosis.
 
okay so i didn't try the visegrip method i just went out and got a new master. It was only 20 bucks so i figured i might as well just get it. Well anyway i bench bled the master then bled the brakes and now ive got an even worse pedal. There also doesn't seem to be as much pressure in the rear lines. what do you think proportioning valve or stuff in the lines? These brakes are going to drive me to insanity.
 
SirDan said:
okay so i didn't try the visegrip method i just went out and got a new master. It was only 20 bucks so i figured i might as well just get it. Well anyway i bench bled the master then bled the brakes and now ive got an even worse pedal. There also doesn't seem to be as much pressure in the rear lines. what do you think proportioning valve or stuff in the lines? These brakes are going to drive me to insanity.
Click to expand...

Low pressure to the backs, but good to front or just low pressure in general?
 
Try bleeding the brakes with the master cyl. cover off. That's what i was doing wrong with my '81 Dodge truck and it solved all of the bleeding problems completely! Now the brakes are very good feeling and work properly.
I was ready to burn it to the ground i got so mad at it, and as usual, it turned out to be something simple!
Man, was i choked at myself after that, but relieved.
Tom.
 
For $20, the master cylinder you purchased must be a "rebuilt" unit and not new?
 
Dartnut said:
Try bleeding the brakes with the master cyl. cover off.
Click to expand...

I would have it loose but not all the way off, when you let up on the pedal the fluid will shoot up and can mess up what ever paint it hits.

If you started with a new MC and new lines, bench bleed the MC before installing it then you need to bleed the right rear first, then the left rear, then the right front and the left front being last. You always do the farthest from the MC first or you will suck air into the ones you just bled.

Have someone work the pedal for you and before you have them pump it up loosen the bleeder and have them push the pedal to the floor and hold it till you tighten it, do this three or four times before you have them pump it up, this will move more air out quicker so it will be easier to get a pedal.
 
ramenth said:
Low pressure to the backs, but good to front or just low pressure in general?
Click to expand...
Good front pressure.

Dartnut said:
Try bleeding the brakes with the master cyl. cover off. That's what i was doing wrong with my '81 Dodge truck and it solved all of the bleeding problems completely! Now the brakes are very good feeling and work properly.
I was ready to burn it to the ground i got so mad at it, and as usual, it turned out to be something simple!
Man, was i choked at myself after that, but relieved.
Tom.
Click to expand...
I haven't tried that yet. I will try it and see what happens.

6pk2goDemon said:
For $20, the master cylinder you purchased must be a "rebuilt" unit and not new?
Click to expand...
Yes it is a rebuilt.

thanks for all the quick replies! maybe ill be on the road in the near future:cheers:
 
Give what dartnut told you a try. Hope it helps. If not, then prop valve may be sticking.
 
Since the master is rebuilt and not new, maybe now try to isolate it by clamping the brake hoses. I hate rebuilt m/c and avoid them like the plague....LOL

Good luck....plenty of suggestions for you to try.
 
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