Anyone know what the brake line psi should be at the caliper?
- Thread starter pamo61
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ptschram
Well-known member
ptschram
Well-known member
I can't find an exact number (and don't have time to look for it) for the Discos, but the Range Rovers with electric assist run at a maximum pressure of 2466 PSI or 170 BAR.
To be honest, I strongly suspect that looking for an absolute number might indicate you're barking up the wrong tree. I've fixed brakes on various vehicles for the past 40 years and have never needed to measure absolute pressures.
Maybe you should start with what your truck is doing that you don't want it to do.
To be honest, I strongly suspect that looking for an absolute number might indicate you're barking up the wrong tree. I've fixed brakes on various vehicles for the past 40 years and have never needed to measure absolute pressures.
Maybe you should start with what your truck is doing that you don't want it to do.
Thanks for the additional info. The truck does not stop as well as it did last week. The booster tests out OK (but going to do some more detailed checks) and no other or mechanical issue seems to be bad enough to be found. Pedal feels good, truck just doesnt want to stop. Just wanted to know where it should be as a basic troubleshooting step. It is currenty about 800psi with the pedal pressed firmly. Thanks again.
-p
-p
800 psi isn't enough for a four wheels disc brake system like our rovers, you need to get at least 1000 psi.
A bad booster will give you a hard pedal feel.
To make sure your power booster is working properly, with the truck off, pump your brakes 2-3 times then hold the brake pedal down while you start up the disco. You should feel the pedal drop slightly indicating that it is functioning properly.
Since boosters work off of vacuum, make sure you don't have a vacuum leak.
Boosters need a minimum of 18" of consent vacuum.
Check vacuum at the manifold...normal vacuum reading at manifold is 18"-22".
A bad booster will give you a hard pedal feel.
To make sure your power booster is working properly, with the truck off, pump your brakes 2-3 times then hold the brake pedal down while you start up the disco. You should feel the pedal drop slightly indicating that it is functioning properly.
Since boosters work off of vacuum, make sure you don't have a vacuum leak.
Boosters need a minimum of 18" of consent vacuum.
Check vacuum at the manifold...normal vacuum reading at manifold is 18"-22".
How are you measuring your brake line pressure? ie: what kind of guage are you using and where is it tapped into the hydraulic system?
edit: I see you are looking for psi @ the caliper. Nevermind.
edit: I see you are looking for psi @ the caliper. Nevermind.
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PT is right. In my 17 years in the business, I have resorted to checking brake hydraulic line pressure only a couple of times, and in those cases, that was not the answer to the vehicle's braking problem.