How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Joe Your Own Question
Joe, RV Technician
Category: RV
Satisfied Customers: 796
Experience:  Associates Degree in Automotive Technology , 18+ years as RV and Commercial Bus Technician
Type Your RV Question Here...
Joe is online now
A new question is answered every 9 seconds

The park brake stopped braking. The vehicle will roll if you

Customer Question

The park brake stopped braking. The vehicle will roll if you don't have a foot on the brake peddle. I was told that parts and labor to fix it would be over $2,000. Is there a modification to install a manual park brake with alarm?
JA: Have you checked the fuses? Is your battery fully charged?
Customer: The estimate was given to me by Rush truck service in Idaho Falls. I assume they checked for electrical continuity. A different mechanic is now presently waiting response for replacement parts to give me his estimate. I would like to eliminate the existing hazard park if simple and not expensive. This is on a church bus and after reading the reports of failed brake application while traveling at high speed, I'm concerned.
JA: What is the model/year of your RV?
Customer: Our bus is a year 2000 work horse chassis with a GM engine.
JA: Are you fixing your RV yourself? What have you tried so far?
Customer: No, I researched the system for knowledge purpose. I too it Rush trucking service for estimate for repairs.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Rush Trucking installed new park brake pads a few months ago. The park brake was working OK until recently.
Submitted: 14 days ago.
Category: RV
Expert:  Joe replied 12 days ago.

Hello , my name is Joe.

If the vehicle will roll , then that usually means that the park brake shoes have been worn away again.

An estimate of $2000.00 sounds like they may be including a new park brake hydraulic pump assembly in the estimate. Most often, the root cause of your issue is leaking and/or defective fluid pressure switches.

Typically, when the pressure switches go bad, the electro-hydraulic pump will not be able to keep the park brake released, then the park brake shoes will contact the park brake drum in travel. When the park brake shoes contact the drum in travel, then they will burn away until they will no longer be able to hold the vehicle from rolling.

If the park brake does not hold the coach , then the brake shoes may have been severely worn or damaged from dragging on the drum while in travel.
The park brake shoes are located inside the drum on the transmission tailshaft.
In most cases , the park brake drum will need to be removed , and the shoes inspected for damage. The park brake cable will need to be adjusted as well.

If the shoes are worn away or the drum shows signs of heat damage , then it is likely there is a fluid leak in the auto park brake system that must be repaired as well.

So, you might get away with replacing a few pressure switches, refilling the fluid reservoir, and another brake shoe replacement. But the technician may determine the pump unit is defective, and this part will add about $1300 to the repair cost.

I have heard of manual park brake lever kits and have seen them on the internet, but do not have any personal experience installing them.


Customer: replied 12 days ago.
Thanks Joe, you said you have heard of manual park brake lever kits and have seen them on the internet. Can you direct me to a connection?
Expert:  Joe replied 12 days ago.

Here is a web address for a conversion kit that uses an air compressor and an air applied park brake actuator:

This rv forum does contain some limited information on converting the auto actuator to use a floor mounted manual lever.


Customer: replied 12 days ago.
Thanks Joe I'll contact these references.
Expert:  Joe replied 9 days ago.

The auto-park system is somewhat complicated, but there are alternatives out there.

Please let me know if I may be of any more assistance.

And remember to rate my service, so I can receive credit for my help.

Thank you

Related RV Questions