WOW lost brake assist while towing

[FBFISH]

Talk about exciting! Lost my brake assist while towing 10,000 lbs. Seems like the vacuum hose from the vacuum pump tp the booster got spongy and must have collapsed. Glad I had my E brake on and had some room. Also, a BIG thanks to the lister who reported on this problem several months back. NAPA had some neopreen hose which did the trick. I only replaced the section of hose from the vacuum pump to the plastic vacuum "T". The rest looked ok. I will get the rest when I get home. A couple of questions: 1) what are symptoms of a bad check valve at the booster? 2) where does that vacuum hose which "T"s of the booster vacuum supply go?

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1995 2500 Auto 4X4 Ext Cab, Sun Coast torque converter, Trans Go shift kit,Jacobs E brake,BD Auto Lok,Prime Lok fuel filter relocate, Boost/EGT and transmission fluid temp gauges, and Mag-Hytec transmission pan/rear end covers

 

[sam peterson]

The function of the check valve is to hold vacuum in the booster in case the motor quits. It should give you 1 or 2 pumps on the pedal with assist, After that its use both feet. The best way to check it is to run engine and shut off. You should have a couple of pumps with assist.

 

['956Wheel]

Yeah, the vacuum hose on my '95 got "fat and spongy" right at the pump, I put a piece of fuel/vapor hose in its place. Such a critical component, (safety), and they phucked up!! Scary! What else is there..... got the throttle cable changed after a stuck throttle in rush hour. Ahh, I guess the beast is designed to go... . not stop!

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9535hundred

 

[LandShark]

If your 95 was built prior to June 1995 it may be part of the vacuum pump check valve recall. The problem was that oil from the vacuum pump would leak into the rubber lines and they would get soft and collapse (and could also wreck the rest of the vacuum system).

My 95 was a month away from the recall dates and DC said they wouldn't help. I had to replace the same line and upon inspection, found a few drops of oil in it!

There is an additional small black plastic check valve mounted on the brake vacuum reservoir. DC changed the design on this a few years back. It takes about 2 minutes to replace and it's about $10.

Info on Recall Notice #720: http://www.ecpe.vt.edu/~dfritz/technical/recalls/recall_720.htm

Also see this for booster check valve : http://dodgeram.org/tech/tsb/1999/05-11-99.htm

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1995 2500 SLT Club 4x4, auto, 3. 54, 3600 pound Elkhorn slide in camper, AirLift air springs, Ricka dual wheel adapters (used only with the camper on), K&N, DC tow hooks, Rancho RS9000, Hellwig rear sway bar.
111,000 miles and counting.

[This message has been edited by LandShark (edited 04-22-2001). ]

 

[FBFISH]

Thanks to you folks who helped me out on this. I will finish the repair when I return home.

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1995 2500 Auto 4X4 Ext Cab, Sun Coast torque converter, Trans Go shift kit,Jacobs E brake,BD Auto Lok,Prime Lok fuel filter relocate, Boost/EGT and transmission fluid temp gauges, and Mag-Hytec transmission pan/rear end covers