Engine/Transmission (1998.5 - 2002) BD brake is weak

[Ted Constantine]

My BD brake on my 2001 is not holding back like it used to. I have cleaned the vacuum solenoid to no effect. Ideas? Do I need to check the back pressure it is producing? And how would I do that?



TIA

Ted

 

[24VChev]

Yes you should check the back pressure. You need a 0-30 gauge as a minimum. I use my 60 psi boost gauge with a solenoid valve on it to switch between boost and brake pressure so I can look at my brake pressure all the time. Just make sure that you use 2 feet of steel tube off the brake valve so you don't melt the plastic hose.



To check the brake pressure install the gauge on the 1/8 ntp port on the valve. With the engine at operating temp turn on the brake while at base idle. it should be about 25 psi. If you test the pressure while driving it should be a max of 60 psi.



To adjust the pressure you need a 5/16 and 1/2 wrench. To raise the pressure make the rod shorter 1 turn at a time. to lower the pressure lengthen the rod. Release the vac on the brake valve with then engine off. Push in the little test button on the center of the solenoid valve, this makes it easier to adjust.



Malcolm

 

[MRose]

Check your hoses also. Mine had cracked from exhaust heat so I replaced them with some multi purpose hose, good heavy hi temp stuff. Made a big diffrence.

 

[Ted Constantine]

Thanks guys, I'll give it a try when I get back to where the truck is parked right now. I have always wanted to have a gauge hooked up to it but have never gotten around to adding more gauges.



Ted

 

[robertyoke]

check for leaks at the manifold and the turbo. check all six ports, the back two cylinders like to have the bolts fall out.

also look for a crack at the bottom of the manifold.



-robert