auto brake, replaced switches, relay, leaks and still problems! please help

[jcramphorn]

Hello

Sorry Another auto park brake problem! Rv is a 2000 31ft.

Today I have replaced the green switch, the grey switch and the relay and still problems

No leaks in the system and the pump runs, pressurizes and releases the brake as it should but the auto brake light stays on all the time (flickering) and every minute or so will run for 30 secs or so.

Definately no leaks in the sytem....could it be a solonoid problem or a pump problem maybe?

Am in England so parts and advice are very hard to come by!

Thanks

[dieselclacker]

jcramphorn, You need to contact old used bear concerning your auto park brake problem. See the sticky at the top of the topic index on this forum. oldusedbear11@charter.net

Dieselclacker

[RVtomtom]

Just saw a post from oldusedbear indicating the email provided in this thread is the best one to reach him. Let me tell you if he can't identify your problem with autopark then nobody will. Contact him and save yourself grief. PS sounds like it may be the solenoid. Think about adding the genie three lamp circuit that he will send you.
Tom

[jcramphorn]

Thanks for the replys,

Found the fault,

There is a spring between the green switch and the pump that was missing, replaced the spring, every things working good

Thanks

[RVtomtom]

Good to know what the auto park circuit does when you miss that spring. I will add this to my RV Faults spreadsheet.
Tom

[oldusedbear]

This little spring (or lack of it actually) has caused a lot of grief from time to time. It is so small that it is easily lost when the aluminum hex adapter is removed. What happens is that the adapter into which the pump motor switch is screwed, may come out in the process of removing the switch (RGS), The spring falls unoticed and the system is reassembled without the spring. This causes the chattering and rapid cycling.

Bottom line is to remove ONLY the RGS and not the fitting behind it. If you DO remove that hex adapter, be on the watch for the little bitty spring. It is about 5/16 ind dia. and about 5/8 long. Pretty fine wire so is easy to miss.

oub

[max49]

Thanks for sharing that information and sharing with us what the fix for your AAPB OUB and JCRAMPHORN. It seems like we're all gonna need as many tips for repairing the autopark as we can get. Thanks again.

[DriVer]

I ws recently speaking to a P Series owner and he shared with me that he hasn't replaced an electric hydraulic switch in quite some time. What he told me, I found to be quite enlightening but I remain skeptical.

He told me that he does not overfill his fluid reservoir and this alone he believes is what is extending the life of the switches on his motorhome. In his experience and opinion, if the fluid is allowed to return to the reservoir unimpeded by being overfull, he believes this to be the key to his success.

[RVtomtom]

Sounds interesting but with 1200 lbs pressure blowing back into the reservoir really can’t say a partial or full level would make much of a difference. Kind of the same thing as your radiator ??? Dirty or water tainted fluid may be another factor as well.
TOM

[DriVer]

[QUOTE=RVtomtom;996440]Sounds interesting but with 1200 lbs pressure blowing back into the reservoir really can’t say a partial or full level would make much of a difference. Kind of the same thing as your radiator ??? Dirty or water tainted fluid may be another factor as well.[/QUOTE]Just sharing what was relayed to me, I have no way of verifying the claim. The owner did seen to be convinced that his strategy was working for him. Best thing about this strategy, it doesn't cost any money to implement.

[oldusedbear]

Inside the RGS, there is a sort of diaphragm made up of two layers of thin plastic. This diaphragm receives the full pressure of the system - - as much as 1600 psi in a normal system. Over time, the plasitc distorts under the pressure, and eventually cracks - - allowing the ATF to get thru the diaphragm and into the main body of the switch. As soon as the crack appears, the pressure of the ATF is equal on both sides of the diaphragm, and the switch (normally on) is now essentially locked ON. Now, the pressure goes above 1600 psi to the limit of the pump - - maybe 2000 psi or so. This very hi pressure usually causes the RGS to mechanically rupture, leaking ATF onto the ground in many cases. The same extra hi pressure will frequently also take out the diaphragm in the Light Switch which is of similar construction. I would suspect that it may also lead to failure of the actuator seals.

The above sequence of events is why you should never drive your coach with the AutoPark Light ON unless you know exactly why the light is ON.

oub