1995 F800 Lucas Girling brakes

[Dave Neubert]

My truck started making a loud wining noise only when parking brake is released it also is building up a lot of heat in he hyd. system traced the sound to the unitized control valve just to the right of the master cylinder. anyone have a exploded view of this valve I'm assuming that something is stuck or blown in there causing the wining and heat build up

 

[heymccall]

Bendix HR-1 valve

Some info here

F-800 Lucas Girling Brakes

I have a 1989 F-800 with the Lucas Girling brake system. The line that comes out of the hydromax into the Hydraulic relay is building up too much pressure I believe. I put a new line on it that was rated at 315 PSI and it started to bubble out of the side like it was about to blow. I then went...

www.heavyequipmentforums.com

 

[Dave Neubert]

thanks is this kit available I can' find anything

 

[Tyler d4c]

thanks is this kit available I can' find anything

If I where a betting man the parts for Lucas brakes are probably discontinued. I looked up the number and I sure can't find anything.

 

[Dave Neubert]

Ok guess I will find a used one

 

[heymccall]

This one says they'll rebuild yours.

BENDIX HYDRAULIC BRAKE VALVE ( HR-1 )

hydraulic brake valve bendix bosch HR1 lucas brake system

www.powerbrake-drivetrain.com

 

[Old Doug]

Just when you think all those should be in the junk yard someone is steal trying to use one. I have a set of manuals on the Lucas Girling some were . If that was my truck i would put a park brake on the trans and replace the rear brakes or junk the truck.

 

[Dave Neubert]

Well I'm thought about replacing the rear end and adding a park brake rebuilt the rear brakes about 6 months ago a little over $2.000 in parts

 

[Junkyard]

My ford service truck has them. I’ve been able to get some stuff through O’reillys. Calipers, wheel cylinders etc. The stuff is out there it just takes a little digging to find it. It can be a cantankerous system at times.

 

[Dave Neubert]

I just wheel cylinders on the drier side again after 6 months and the are leaking again after a week. Found out that there is a residual check valve that you can add that holds 5-10 psi that is supposed to stop this.

 

[heymccall]

I never heard about adding a residual check valve to the durapark system.

You're obviously versed in servicing the rear brakes.
First thing I always found wrong when a wheel cylinder was leaking was that, when parked, the park chamber was extended further on the failed side.

Simply run both cage bolts in until touching, while engine is off. They should both be same extension. The side that went in further was always the leak side (brake fluid, not oil).

Adjustment of the wheel cylinders unevenly is where most issues lie. Out of adjustment leaves one cylinder extending way to much on every brake cycle.

I always had to leave the axle seal out, and keep trying the drum fit to actually get them close enough.

 

[Dave Neubert]

The check valve is on the service brakes that is what Is leaking brake fluid not ATF

 

[Dave Neubert]

You tube has a video fixing my leaking Lucas Girling brakes

 

[heymccall]

Whichever park chamber is in further when parked will usually point to the side leaking brake fluid....that side is usually found, by me, to have the one brake cylinder out of adjustment, causing that brake cylinder to stroke too far at each application.
Chamber rod depth can be used as a quick and dirty guide to find which side is out of adjustment, at the brake cylinders.