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Topic: Parking break switch leaks all my air when pushed in (Read 2001 times) previous topic - next topic

Re: Parking break switch leaks all my air when pushed in

Reply #25 –
Quote from: Mogan David –
Now I can't figure out how to dismantle the pieces and parts from the spring-loaded shaft.
If the valve you are trying to rebuild is not original Bendix, then it might be different construction inside.  The rebuild kit may not work?

Link to my thread below where I rebuilt our original PP-1 valve.  The photos of the my disassembled valve might help you, or not.

I don't remember there being anything tricky about taking it apart, but it was 4 years ago, so...

Bendix PP-1 Repair Kit
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Parking break switch leaks all my air when pushed in

Reply #26 –
Have a question on the PP-1 Brake Valve.  I was going to order a valve to keep as a spare.  I see they have 20, 40, and 60 PSI available.  Anyone know what PSI valve is correct ?
Mark & Bev
2001 U295 36' Slide
Cummins ISC 8.3 350HP
Build #5802
Jeep Wrangler Toad

Re: Parking break switch leaks all my air when pushed in

Reply #27 –
Quote from: MarkC –
I see they have 20, 40, and 60 PSI available.
Mark,

I am pretty sure 40 PSI is the correct parking brake "automatic set" pressure on Foretravel coaches.  I know I have seen that documented some place, but I can't recall where off the top of my head.  When tested (on our coach) the knob pops out at about 35-40 PSI.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Parking break switch leaks all my air when pushed in

Reply #28 –
Believe that 40 lbs is the standard most trucks use, if pressure drops below 40 the emergency spring brakes are activated, stopping the vehicle. it can be a lower setting as low as 20 lbs but 40 is what most air brakes are set at. The air pressure holds the parking in the off position pushing against the springs that are trying to close all the time. If it's set at 60 lbs you may under heavy braking (with air leaks and a bad compressor) loose enough pressure to bring on the emergency brakes for a very sudden stop, not a good scenario.
So, it's probably a 40 lb

David & Emma Roche
Dino (Golden Doodle)
1999 U270 WTFE 36' Build # 5534
Xtreme "Lights, Stripes & Roof"
Motorcade# 18321
Dayton, Ohio
Towd: Jeep Grand Cherokee
Two Townie Electra Bikes

Life is made to enjoy, the Foretravel helps!

Re: Parking break switch leaks all my air when pushed in

Reply #29 –


well...
that didn't work...
have to figure out how to attach photos

Chuck,  thanks.  I had seen those photos before I posted.  Your valve is different.  When rear cap is removed from it, the threaded end of the shaft, with lock nut, is right there.  When the rear cap of mine is removed, I'm looking at the rubber disc.  thought it might pop off with an O ring removal tool.... NOT
MPParts | Haldex KN20021 Parking Brake Valve | KN20021

The kit:  Haldex Reman Valve Repair Kit - 281126K
Mogan David
1999 U295 36'

Re: Parking break switch leaks all my air when pushed in

Reply #30 –
How to find a leak.

1: Put soapy water on it and watch for bubbles

2: Get a length of plastic tubing.  Put one end in your ear put the other near where the suspected leak is.  It works.

3: Buy one of these:
Air and gas leak detection set in a case - LD 400

Little over the top but then who am I to criticize as I have one!

Keith
Keith, Joyce & Smokey the Australian Cattle Dog
1995 U320 SE Extreme 40' WTBI Build # 4780, with a Honda CR-V hopefully still following behind.
Motorcade # 17030
FMCA # F422159

Re: Parking break switch leaks all my air when pushed in

Reply #31 –
"Snoop" is great product....
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)