braking issue

[skywalker]

Okay, I've had this problem since day one with my brakes.
When I go to stop I have to "pump" the brakes to get good strong pedal feel when braking.

I originally had drums and the problem continued after my disk brake conversion. I've replaced most of my brake lines, have no apparent leaks and a new master cylinder. I've bled the living piss (figuratively) out of the brakes. I did a bench bleed on the master cylinder when I installed it.

what the heck is going on?

 

[dj747]

I had a similar problem and it turned out to be the power brake booster. I can't figure out why pumping had an effect, but it fixed mine. Time for a new vacuum booster?
Good luck
Dan

 

[skywalker]

manual brakes. So booster is ruled out.

 

[Ozsum2]

new lines, new MC, gotta still be air in the lines or it is getting in there from an un-sealed breeder screw.

 

[skywalker]

I'll double check that (in fact I think I'm goint to get some speed bleeders) but I swear, I've done everything I could to prevent that. I actually snapped a bleeder screw in half tightening them down.

 

[Cdaniel]

Do you still have rear drums? Could be out of adjustment, worn linings or drums turned out to much. Or a combo thereof.

 

[Cdaniel]

Do you still have rear drums? Could be out of adjustment, worn linings or drums turned out to much. Or a combo thereof.

Nevermind, I just noticed the 4 wheel discs in your sig line.

 

[WORTH]

Nevermind, I just noticed the 4 wheel discs in your sig line.

IF it's 4 wheel disc , does it have a master capable of filling the rear calipers or is it a drum rear master? Calipers take more fluid than wheel cylinders

 

[Ozsum2]

new lines, new MC, gotta still be air in the lines or it is getting in there from an un-sealed breeder screw.

"breeder screws?" I really need to start proof reading.

 

[skywalker]

"breeder screws?" I really need to start proof reading.

Don't worry, I do it too. It is a sign of superior intelligence.

I'm not sure if my master cylinder is big enough indeed (anyone want to suggest a good one for 4 wheel discs?) but I had this same problem with 3 wheel drums.

I was looking at a couple of wilwood aluminum ones but none seem that they will easily bolt up.

 

[Ozsum2]

Don't worry, I do it too. It is a sign of superior intelligence.

I'm not sure if my master cylinder is big enough indeed (anyone want to suggest a good one for 4 wheel discs?) but I had this same problem with 3 wheel drums.

I was looking at a couple of wilwood aluminum ones but none seem that they will easily bolt up.

Yea, since you had it B4, I'm thinking it isn't a parts compatibility problem, but a mechanical gremlin thing.

 

[skywalker]

Yea, since you had it B4, I'm thinking it isn't a parts compatibility problem, but a mechanical gremlin thing.

Yes and it's pretty bad too, sometimes the car will barely get brake pressure upon initially pressing the brakes. Not something I'm happy with.

 

[WORTH]

Yea, since you had it B4, I'm thinking it isn't a parts compatibility problem, but a mechanical gremlin thing.

IF you had it before it could have just been the brakes out of adjustment

if you have to pump more than once to get the piston to reach the caliper, either the piston is too far away from the caliper or the master is not putting out enough fluid to push it far enough.

If you have air in the system, you'll always have a spongy pedal regardless of how many times you pump it, because air compresses.

 

[monk302]

I was having a similar problem with mine and what had happened was I put the calipers on the wrong side. I switched them and it was fine. I still cannot believe I put them on the wrong side. Oh well, I can put someone through the windshield now.

 

[Ozsum2]

IF you had it before it could have just been the brakes out of adjustment

if you have to pump more than once to get the piston to reach the caliper, either the piston is too far away from the caliper or the master is not putting out enough fluid to push it far enough.

If you have air in the system, you'll always have a spongy pedal regardless of how many times you pump it, because air compresses.

Then you'd have air brakes.

 

[68GEETEE]

What MONK said is what happened to me too. Someone had installed the right caliper on the left wheel, and vice-versa, so the bleeders were positioned at 4 oclock instead of 12 oclock. . You can bleed them all day long, lots of fluid comes out, but the air is trapped in a pocket ABOVE the bleeder screw. . NO pedal. . I reinstalled them correctly, bled them and I have great brakes.

Note, the bleeder has to be at 12oclock position, when it is corrrect, the screw itself will most likely point to the rear of the car.

 

[skywalker]

Only one problem with that: I have wilwoods in front which can go on either side and my rears are from a newer ford and they're on correctly. The pedal is spongy at all times...but to feel any pressure at all in the pedal, I have to pump it up. Oh well, maybe I'll try doing a vacuum pump bleed tomorrow.

No one has yet to suggest a good master cylnder for 4 wheel discs.

 

[Cdaniel]

Only one problem with that: I have wilwoods in front which can go on either side and my rears are from a newer ford and they're on correctly. The pedal is spongy at all times...but to feel any pressure at all in the pedal, I have to pump it up. Oh well, maybe I'll try doing a vacuum pump bleed tomorrow.

No one has yet to suggest a good master cylnder for 4 wheel discs.

Maybe your master cylinder needs those residual pressure check valves?

 

[67coupestang]

Don't worry, I do it too. It is a sign of superior intelligence.

I'm not sure if my master cylinder is big enough indeed (anyone want to suggest a good one for 4 wheel discs?) but I had this same problem with 3 wheel drums.

I was looking at a couple of wilwood aluminum ones but none seem that they will easily bolt up.

I recomend one from a 98ish explorer. Its aluminum bodied, with the plastic res, I think its a 1 1/8" bore and the ports are on the outside, not facing the engine.. It will have a weird switch but just leave it unhooked. best of all about $25 in a yard.

 

[skywalker]

finding a junkyard with an explorer might be an issue for me. So I might have to buy new, with this in mind does anyone have any suggestions? Aftermarket even?