J71 Auto Park Brake Leak!

[iRV4FUN]

Just about the time I started bragging about how dependable my P-32 has been, the buzzer and beeping (!) Automatic Apply Parking Brake goes off. After a few miles the beeping stops and then eventually the buzzer and (!) dash light goes out. Braking seems normal and the auto park brake holds the rig on a steep incline.

I understand that 90% of the time it's the Pressure Switch. Except the Pressure Switch is dry and nothing is coming out the connector.

Yet, red ATF fluid is dripping off the backside of the clear reservoir.

Seems the clear fluid reservoir and the black park brake pump assembly is where the fluid is seeping from. Is this possible?

Is there a replaceable seal between the fluid reservoir and pump assembly?

[DriVer]

Originally Posted by iRV4FUN

Is there a replaceable seal between the fluid reservoir and pump assembly?

Reach out for OldUsedBear our resident AAPB expert! He's all to happy to work through this problem with you.

[edgray]

oldusedbear@oemys-performance.com has the answers to your questions-FREE, too!

Ed

[oldusedbear]

There is usually an O ring between the tank and the pump. Most reservoirs have a single screw coming up thru the bottom of the tank - - Check for tightness.

oub

[iRV4FUN]

Originally Posted by oldusedbear

There is usually an O ring between the tank and the pump. Most reservoirs have a single screw coming up thru the bottom of the tank - - Check for tightness.

oub

Thanks, oub

Unfortunately, I've got the reservoir without the bottom screw. I tightened the 4 top phillips screws and still seeping. I guess I need a new O ring and can drop the reservoir and replace.

http://www.westernintech.com/assets/108 Series vertical A B C D generic exploded view drawing.pdf

The old fluid in the reservoir will be removed and replaced with fresh new ATF fluid. Isn't it a good idea to flush the entire system? I'm not sure of the tools, nor procedure.

I wounder if the Ford repair shop put DOT3 in my Auto Park Reservoir. They had a knucklehead bleed my brakes in the wrong order. Gee that DOT3 might have chewed up my O ring

[oldusedbear]

It would help me out if you could contact me at either the link in the post by Ed Gray or at oldusedbear@nwtec.com

We'll be glad to work thru your AutoPark problems with you.

oub

[oldpa]

The first thing you need to do is contact Roger (oldusedbear). He knows more about our autopark systems than most of the GM and Workhorse techs.
Credit for following info. goes to Roger :
DO NOT let anyone work on the autopark before you understand how it works. Just throwing parts at the problem can and will get expensive.

I had a leak from my autopark pump too, and the bottom line was a $49.00 part cost my extended warranty $720.00 just in parts.

Here is a picture of the crack in my tank and part of my email to Roger.
-----------------------------------------------------------------------------------------
I have a 2002 Workhorse P-32 with 53,000 miles. I sent the motor home to my Workhorse service dealer to have my main brakes checked and if needed, new pads installed.
With the motor home up on the lift he saw that the rear transmission seal was leaking and the auto-park pump was also leaking.
He told me the pump leak was probably from a bad gasket or seal in the pump and there are no service parts available and the ONLY fix was to replace the pump.

The pump from Workhorse was $720.00 plus installation. My extended warranty would pay for the leaking transmission seal and the auto-park pump with me only paying $200.00 total out of pocket. I had the pump replaced and I did keep the old pump so I could see what went wrong with it.

Well, it turns out the only thing wrong was a crack in the tank, so for a $49.00 plastic tank one has to buy a $720.00 part; unbelievable!
-------------------------------------------------------------------------------------------------------------
Back to 8/19/2010

Roger gave me the contact person at Parker Hannifin Corp., Oidyne Divison
From him I got the part numbers for a tank replacement kit ( tank, O ring, cap and bolt )
That part # is---”7750772 kit reservoir C rev std”
My pump was like yours and used the four screws to hold the tank to the pump. The current tanks bolt from the bottom.
The cost for the kit is $49.13 plus shipping

The tank comes off by removing the four screws from the top, piece of cake. Now look for any cracks. If you find any then that’s probably that’s what is causing your leak.
The new tank bolts right up to the old style mount and takes about 10 minutes to install.

Good luck, Greg

[ddtcat]

Yes I just talked with Larry at the Oidyne division , his direct number is 763-531-3578 He explained the part number is actually 775072 you can also request the kit part number 775622 they are both the same for the resevoir and parts. Still under $50.00 plus shipping. You have to order from a Parker division store or parts supplier for parker products.

[frederick w]

Hi
ddtat, do you think the O-ring for the sump, with the 4 hold-down
screws, would be the same for my sump with a single hold-down screw?
I have a P-32, J71

Thanks

Fred from Pasco, Wa.

[ddtcat]

Cannot give you any info on that,was just giving the correct part numbers. try calling Larry he may be able to help.

[iRV4FUN]

One of my schematics of the Parker 108 shows both design reservoirs. The bottom screw reservoir seal part# 410578 and the 4 screw Res O-ring 238-70 part# 411237. So call Larry and have your reservoir part number handy so he can look it up for you.

========== ==========

Just received my new reservoir and o-ring. I found an aircraft parts warehouse AeroCraft Parts & Supplies Home Page at 1-866-659-AERO with both components. Very prompt service! I called the order in because their web site had problems with ordering. The gal their will call you back as I think they using an answering service. They are out of Redmond Oregon with prompt two day delivery and for a grand total of 26 bucks.

My experience is the big box hydraulic parts houses are understandably not very excited to take a couple of dollars from some sorry J71 RV owner. Hardly worth their time. But, the areocraftparts gal will! Hope she gets some more calls!

According to the people at Parker the 4 screw reservoir Part# 413183 is an upgrade from the bottom screw model.

Another upgrade is the cap. I'm getting one of those breather caps as there can be a fair amount of pressure in the tank when the ATF is returned. I'm also sold on the need to make sure I don't overfill. There are very faint MAX and MIN markings on the side that will be colored with a permanent marker.

I didn't go for the 50 buck kit. I looked at the screens and they are clean and the phillip screws are being replaced with stainless steel bolts so I can get a socket on them vs. a screwdriver.

Because I'm a Mobile1 freak I'd like to upgrade, but, will keep it Dexron III.

Ya know what I'll be doing today!

[Oemtech]

I looked at their site but really couldn't tell where the pump parts were. Any insite?

[iRV4FUN]

Originally Posted by oemtech

I looked at their site but really couldn't tell where the pump parts were. Any insite?

Try this: Search Form

Or enter into the search box the word "reservoir".

[Oemtech]

It returns ... nothing found on my system.