brake pressure tester

TreeClimber · Mar 8, 2013

Anyone have a pressure tester for brakes? How does the tool work?
On a disc brake system, does it screw into the caliper bleed screw? Or..?

Recently changed my front differential, and went with bigger calipers and rotors. Got the system finally bled, and have got brakes that stop. But still easily drive thru the brakes when in low range. My question is simple, how much pressure do I have at the calipers?

zukkev · Mar 8, 2013

Yes, they tap into the bleeder screw...What Master Cyl are you running? We ran into a similar issue with Jim Paget's YJ...Ended up removing the pill in the prop valve and going with a different Master to solve it...Hope that helps...

TreeClimber · Mar 8, 2013

zukkev said:
Yes, they tap into the bleeder screw...What Master Cyl are you running? We ran into a similar issue with Jim Paget's YJ...Ended up removing the pill in the prop valve and going with a different Master to solve it...Hope that helps...

Already did all that; Vette Master, dual diaphram booster, no proportioning valve, dual piston front discs, single piston rear discs, etc.

Anyone got a tester that they are willing to loan for an hour or two?

PORTER · Mar 8, 2013

TreeClimber said:
Already did all that; Vette Master, dual diaphram booster, no proportioning valve, dual piston front discs, single piston rear discs, etc.

Anyone got a tester that they are willing to loan for an hour or two?

Tony, are you sure you dont have too much gearing causing you to push thru your brakes?

benw1 · Mar 8, 2013

Push in the clutch when you want to stop...

TreeClimber · Mar 8, 2013

PORTER said:
Tony, are you sure you dont have too much gearing causing you to push thru your brakes?

I do have that problem. True. And I've known that was (is) my problem for years.

However, when I just installed the Dynatrac 60 with the 'big brake kit', I thought it would help. But I don't see any improvement.

This caused a 'curiosity' question, as to exactly how much pressure is on the caliper/pad?

I've always used the assumption it was too much torque/gearing. If I check the caliper, and I've got 800psi, then YUP. But if I check the caliper, and I've only got 100psi, then NOPE.

And if someone had the tool, it would seem an easy item to verify?

TreeClimber · Mar 8, 2013

benw said:
Push in the clutch when you want to stop...

What clutch? (I kick it into 'N')

benw1 · Mar 8, 2013

Well in that case, you might need a lower idle speed or a higher stall converter. (if your brake pressure checks out)

PORTER · Mar 8, 2013

TreeClimber said:
I do have that problem. True. And I've known that was (is) my problem for years.

However, when I just installed the Dynatrac 60 with the 'big brake kit', I thought it would help. But I don't see any improvement.

This caused a 'curiosity' question, as to exactly how much pressure is on the caliper/pad?

I've always used the assumption it was too much torque/gearing. If I check the caliper, and I've got 800psi, then YUP. But if I check the caliper, and I've only got 100psi, then NOPE.

And if someone had the tool, it would seem an easy item to verify?

Whats your crawl ratio. It sounds to me thats your prob. It doesnt hurt to do the check brake thing , but if you had the prob before and then after a brake upgrade well ya know. A higher stall TC may be in your future.

TreeClimber · Mar 9, 2013

PORTER said:
Whats your crawl ratio. It sounds to me thats your prob. It doesnt hurt to do the check brake thing , but if you had the prob before and then after a brake upgrade well ya know. A higher stall TC may be in your future.

Yeah, I have too much torque and a too low crawl ratio, which exceeds my brake clamping capacity. Have had that issue since I first built this jeep 10 years ago.

I still need to burnish these new brakes. That should really help with clamping capability.

Installing a new TC is a PITA. Plus, most of my actual wheeling is slightly off idle, in 2nd or 3rd gear, low range. So a 'high' slip TC will be always slipping, which generates heat/wear.

I'm probably just going to leave everything the same....
However, I really am curious as to how much PSI really is at the calipers.

PORTER · Mar 9, 2013

TreeClimber said:
Yeah, I have too much torque and a too low crawl ratio, which exceeds my brake clamping capacity. Have had that issue since I first built this jeep 10 years ago.

I still need to burnish these new brakes. That should really help with clamping capability.

Installing a new TC is a PITA. Plus, most of my actual wheeling is slightly off idle, in 2nd or 3rd gear, low range. So a 'high' slip TC will be always slipping, which generates heat/wear.

I'm probably just going to leave everything the same....
However, I really am curious as to how much PSI really is at the calipers.

I completely hear where your coming from as I have a similar issue with my buggy. On a flat I can stop in 1st, but coming downhill in 1st I will push thru. My remedy is to put my trans in 2nd in this situation(Turbo-400 manual valve body). IIRC my crawl ratio is 45-1. Good luck.