Wilwood master cylinder? Please help!

[garykirby25]

Need some help guys! I bench bled my master and bled the brakes. I've got no pedal on the first pump, but after that I start to get some pedal. I've bled them like five times and get liquid and no air. Theres no play from pedal to master. Any other thoughts?????


Wilwood 1inch bore no booster
Wilwood combination proportioning valve

Thanks
Gary

[john]

Sounds like they an adjustment.

[Fitz]

Originally Posted by garykirby25

Need some help guys! I bench bled my master and bled the brakes. I've got no pedal on the first pump, but after that I start to get some pedal. I've bled them like five times and get liquid and no air. Theres no play from pedal to master. Any other thoughts?????


Wilwood 1inch bore no booster
Wilwood combination proportioning valve

Thanks
Gary

Drum or disc?

[garykirby25]

Originally Posted by Fitz

Drum or disc?

Disc

[70SBC10BOB]

Try capping where lines go into the master. If the pedal is still goofy, you have a bad master. Wilwood has had some problems with their masters in the past.

If the pedal is solid, connect one line and try again.

If everything is still ok, connect the last line. If it goes south, you know which end of the system is the problem.

One quick question. When you did the bench bleed, did you bottom out the master? If you didn't, you may be fighting a bubble at the end of the master.

Good luck,
Bob

[garykirby25]

Thanks for the reply, I'm guessing that I didn't bench bleed it well enough. I did long slow stroke until no air bubbles, but I think that has to be it. I've got no brake on first pump and good brake after two. That would suck if it was the master, it's one of those new parts that set in the garage for a year.

Originally Posted by 70SBC10BOB

Try capping where lines go into the master. If the pedal is still goofy, you have a bad master. Wilwood has had some problems with their masters in the past.

If the pedal is solid, connect one line and try again.

If everything is still ok, connect the last line. If it goes south, you know which end of the system is the problem.

One quick question. When you did the bench bleed, did you bottom out the master? If you didn't, you may be fighting a bubble at the end of the master.

Good luck,
Bob

[SierraMtns]

Keep us posted on what you find to be the problem. I have been looking at a Wilwood master for a while.

[Tom Vogel]

Are the bleed screws on the wheel cylinders on top? Silly question I know, but it is easy to get them on the wong side, and then you just cant get the air out.

[garykirby25]

Both rear bleeding screw are here. I've bench bleed my master again, it didn't fix it.Got good pedal on second pump and no pedal on first

[Fitz]

Originally Posted by garykirby25

Both rear bleeding screw are here. I've bench bleed my master again, it didn't fix it.Got good pedal on second pump and no pedal on first

I use the same rear brakes you have and I think I see your problem. Those rear calipers are on the wrong side. Reversing them will put the bleeder on the top allowing the air trapped in them to escape. Then you will get good pedal.

[garykirby25]

Sorry fitz, picture flipped. I can't get it to stay up. The bottom is the left side of picture

[SierraMtns]

Originally Posted by garykirby25

Sorry fitz, picture flipped. I can't get it to stay up. The bottom is the left side of picture

You taking the picture with an Iphone? I think you can take the flipping mode off.

[SierraMtns]

Originally Posted by garykirby25

Both rear bleeding screw are here. I've bench bleed my master again, it didn't fix it.Got good pedal on second pump and no pedal on first

Garykirby25 post up some pictures of the Wilwood master.

[68basket]

if your hand is on the bottom of the caliper, then they are on the wrong side. The bleeder must be on the top side of the caliper or the air will not come out of it.-------never mind i think i saw the pic wrong. hard to tell with the sideways pic.

[Fitz]

E-brake spring at the top, e brake cable connection at the top pointing to the front of the vehicle, bleeder under the ebrake connection and fluid inlet at the bottom is how those calipers must mount. If they don't they are reversed side to side and switching them will place the bleeder at the top.

If the bottom is the left side of your picture then the e-brake spring which is on the left of the picture is on the BOTTOM, not the top as it must be. Take a closer look at the picture I posted!

[garykirby25]

My I pad taking the picture correctly, then its getting turned when I load to the site. I believe that my caliber is correct by what fitz said. I completely rotated my caliper where my bleed screw was at the top and bled them again. Still no pedal on first pump. Getting picture of master, any other ideas?

Thanks,
Gary

[garykirby25]

Master

[Fitz]

Originally Posted by garykirby25

Master

The master reservoir needs to be the highest point in your system and there shouldn't be any loops in the lines to trap air. Your lines from the master to your combination valve might be holding air. I ran mine differently to prevent that.

[67 cst swb]

You need to get the Master Cyl lines changed. So that no part of these lines are above the master cyl ports. The fluid in these lines are draining back into the master cyl, so on the first pedal pump... you refill the lines... then on the second pump it works normally...
You gotta change these before you try anything else... shorten the lines and have them go down hill directly to the prop valve.

Oops... Sorry didn't read post #53 before posting....

[davepl]

Others have hit on what, and I'll tells ya exactly what and why it's happening.

It looks like you're using those Cadillac calipers, or something derived from them, and in my opinion they're the spawn of the devil. You MUST use the parking brake every time you park, as that's how they adjust. And the parking brake must be adjusted PERFECTLY for them to survive and work properly.

But that's not the problem. The problem is you have the calipers upside down, and it's not just that it makes it harder to bleed. With the bleeder screws open you are draining fluid out of the rear calipers, so there's none behind the piston. Then when you're done you go to push the pedal. That backfills the caliper pistons, and it make take a couple of pumps to do it. That's entirely normal - the first time you fill a caliper. You might get away with it on pressure bleeding, but if vacuum bleeding it's going to suck the piston back each time. Even gravity bleeding might, not sure.

In your case I think you're draining that backing fluid because the bleeder screws are on the bottom. Heck, it's even possible it'd work if the subsequent pedal pumps all stay high and hard permanently, but it'd be challenging to do.

Flip the calipers around (which likely means side to side) and re-bleed them. I bet that fixes it.

The factory runs loops in the lines all of the time to allow for things to move around. So I don't think that part is related.

[SierraMtns]

Originally Posted by garykirby25

Sorry fitz, picture flipped. I can't get it to stay up. The bottom is the left side of picture

Originally Posted by davepl

Others have hit on what, and I'll tells ya exactly what and why it's happening.

It looks like you're using those Cadillac calipers, or something derived from them, and in my opinion they're the spawn of the devil. You MUST use the parking brake every time you park, as that's how they adjust. And the parking brake must be adjusted PERFECTLY for them to survive and work properly.

But that's not the problem. The problem is you have the calipers upside down, and it's not just that it makes it harder to bleed. With the bleeder screws open you are draining fluid out of the rear calipers, so there's none behind the piston. Then when you're done you go to push the pedal. That backfills the caliper pistons, and it make take a couple of pumps to do it. That's entirely normal - the first time you fill a caliper. You might get away with it on pressure bleeding, but if vacuum bleeding it's going to suck the piston back each time. Even gravity bleeding might, not sure.

In your case I think you're draining that backing fluid because the bleeder screws are on the bottom. Heck, it's even possible it'd work if the subsequent pedal pumps all stay high and hard permanently, but it'd be challenging to do.

Flip the calipers around (which likely means side to side) and re-bleed them. I bet that fixes it.

The factory runs loops in the lines all of the time to allow for things to move around. So I don't think that part is related.

But what about running the lines higher then the master? Wont that cause air to get trapped in the line?

[davepl]

Originally Posted by SierraMtns

But what about running the lines higher then the master? Wont that cause air to get trapped in the line?

Didn't notice that part, you might well be right. In every application I've seen you need the master cylinder is the highest. In street rods and so on you can put them under the floorboard but it requires check valves in the lines.

So yeah, I'd fix that too. But given the amount of pedal travel I don't think air trapped there would compress that much, but who knows. Fix it all, then it's right.

[Palf70Step]

Originally Posted by davepl

Others have hit on what, and I'll tells ya exactly what and why it's happening.

It looks like you're using those Cadillac calipers, or something derived from them, and in my opinion they're the spawn of the devil. You MUST use the parking brake every time you park, as that's how they adjust. And the parking brake must be adjusted PERFECTLY for them to survive and work properly.

But that's not the problem. The problem is you have the calipers upside down, and it's not just that it makes it harder to bleed. With the bleeder screws open you are draining fluid out of the rear calipers, so there's none behind the piston. Then when you're done you go to push the pedal. That backfills the caliper pistons, and it make take a couple of pumps to do it. That's entirely normal - the first time you fill a caliper. You might get away with it on pressure bleeding, but if vacuum bleeding it's going to suck the piston back each time. Even gravity bleeding might, not sure.

In your case I think you're draining that backing fluid because the bleeder screws are on the bottom. Heck, it's even possible it'd work if the subsequent pedal pumps all stay high and hard permanently, but it'd be challenging to do.

Flip the calipers around (which likely means side to side) and re-bleed them. I bet that fixes it.

The factory runs loops in the lines all of the time to allow for things to move around. So I don't think that part is related.

Originally Posted by SierraMtns

But what about running the lines higher then the master? Wont that cause air to get trapped in the line?

Everything I learning about hydraulics goes along with SierraMtns comments. The loops are OK, but as long as they are lower than the fluid source.

[davepl]

Originally Posted by Palf70Step

Everything I learning about hydraulics goes along with SierraMtns comments. The loops are OK, but as long as they are lower than the fluid source.

Well, if you bled them really fast the viscosity of the oil would be high enough that it'd push the air out of the way. Can you tell I'm a programmer and not a hydraulic engineer? I can spot weird exception cases but add no actual value :-)

[ericjon262]

Originally Posted by davepl

Well, if you bled them really fast the viscosity of the oil would be high enough that it'd push the air out of the way. Can you tell I'm a programmer and not a hydraulic engineer? I can spot weird exception cases but add no actual value :-)

you're best to re-do the lines and get them lower.