Community Forums

Ron03Allegro · 01-09-2025, 08:32 AM

Quote:

Originally Posted by SafariBen

Are you sure it's brake fluid leaking? I would think it would be ATF or power steering fluid from a separate reservoir on the pump in this case, or the power steering system on other models.

So no helpful answers to 1. is the brake fluid reservoir seperate from the autobrake reservoir. 2. Anybody know way to turn off, unplug, pull the fuse on the autopark pump, must be a way but how?

My plan is to drive 7 miles to the nearest autoparts store, and get some dot 3 brake fluid. Put the RV on it's leveling jacks and go access brake reservoir which is hard to access, check level and fill as needed.

My plan also is to disable the autopark pump, if I have to by cutting a power wire to it.

I will be checking back here this morning, hoping someone answers the questions above.

David 70 · 01-09-2025, 09:00 AM

Quote:

Originally Posted by Ron03Allegro

So no helpful answers to 1. is the brake fluid reservoir seperate from the autobrake reservoir. 2. Anybody know way to turn off, unplug, pull the fuse on the autopark pump, must be a way but how?

My plan is to drive 7 miles to the nearest autoparts store, and get some dot 3 brake fluid. Put the RV on it's leveling jacks and go access brake reservoir which is hard to access, check level and fill as needed.

My plan also is to disable the autopark pump, if I have to by cutting a power wire to it.

I will be checking back here this morning, hoping someone answers the questions above.

The regular brake system is totally separate from the auto park system. There is a fuse at the pump that you should be able to remove, otherwise remove the main power cable going to the pump. have you looked at any pictures of the pump? If not, look up Ultra RV and look through their pictures for your coach. People think those systems are complicated but once you understand them, they are a little easier to diagnose but still a PITA. I have had two coaches with them on, one a J71 and now a J72.

Ron03Allegro · 01-09-2025, 10:30 AM

Quote:

Originally Posted by David 70

The regular brake system is totally separate from the auto park system. There is a fuse at the pump that you should be able to remove, otherwise remove the main power cable going to the pump. have you looked at any pictures of the pump? If not, look up Ultra RV and look through their pictures for your coach. People think those systems are complicated but once you understand them, they are a little easier to diagnose but still a PITA. I have had two coaches with them on, one a J71 and now a J72.

thank you very much. So brake fluid is separate reservoirs from brakes and autobrake? I am now going to look at disabling autobrake pump, fyi seems to cycle a lot and then turn off displaying brake red light on dash, but it will run again as some point.

Unplanned Tourist · 01-09-2025, 10:38 AM

David70, I see you have 38J also, but a 2005. I have a 2008 38J. Lucky for me it doesn't have a APB, but a manual one and a park brake built in the transmission.

I had a J71 system on the last MH we had. The actuator cylinder started leaking, so I had to ship it out for repairs. Luckily I didn't have to use the MH while it was gone, but getting the pin out of the clevis was tricky. The puddles of ATF on the ground and mess under the rig was nice to be gone after the fix.

It sort of sounds like the OP has 2 problems if there's brake fluid leaking somewhere.

Ron03Allegro · 01-09-2025, 10:42 AM

Can see the pump .. hooray it is a separate reservoir it was full now it has 1/3 full. What kind of fluid does it use?

There is a connection with two wires and one with ten? can't tell what they disconnect and I do not see a fuse, or how to for sure disable the pump, it is not running now, when if ir does again, I will check back here if not before.
The fluid is wet all over the pump and below.

SafariBen · 01-09-2025, 10:47 AM

The parking brake uses ZERO, NO dot 3 or any other brake fluid. The parking brake is a spring applied MECHANICAL brake. The motor to release it pumps ATF/ hydraulic fluid. If you disconnect power to the motor, it should stop leaking, and the fluid level will not be a priority.

I don't know the system specifically, so I'd check the POWER STEERING fluid level on the main pump on the engine, just in case they use the same reservoir. Can also check the master cylinder brake fluid level, that should be unrelated to this parking brake.

Laggard · 01-09-2025, 11:32 AM

Quote:

There is a connection with two wires and one with ten?

Disconnect the two connection two disable the pump motor., see picture below

David 70 · 01-09-2025, 11:58 AM

the master cylinder for the service brakes, those are the ones you use when you step on the brake pedal, is hard to get to. You need to get up in the left steering tire wheel well and it is way up in there almost to the top of the firewall. There is only about two inches of space above the top of it. That reservoir takes dot 3 or 4 brake fluid. I use dot 4 when I flush the system. Dot 4is synthetic and has a higher boiling point than three. Flushing the system is something that needs to be done regularly. I found out the hard way when I lost brake pressure. You have the same pump that is used on the J72, but it has the J71 type of brake shoes. The J72 on the Allison transmission has a different brake setup on the transmission.
The early Chevy chassis used the power steering pump for pressure to the AAPB but none of the Workhorse chassis did.
The hydro boost for the service brakes does use the power steering pump though.

Ron03Allegro · 01-09-2025, 05:41 PM

I months ago I found the service brake reservoir and replaced the Dot3 there, I used a handy usb pump to pump out and pump new in.

I found j71 pump and reservoir, I have thought that was for my leveling jacks, guess not. The reservoir was full now it is 1/3 and the area around it is moist with fluid. The pump did not run at all today, and the dash shows a autopark light and a red brake failure icon.

A concern now is I do not know if my HWH hydralic leveling jacks use the same pump and reservior as the autopark and I am afraid to try for fear they get stuck down and will not come up and strand me. I do not know of a third pump for the leveling jacks.

David 70 · 01-09-2025, 06:03 PM

The HWH system is another entirely separate system. On my 2000 P32 it was right in the center just ahead of the radiator. If you need oil in it HWH has their own oil, it is the same as dexron just doesn't have any dye in it so it doesn't leave stains if it drips. If you find it, it will most likely say use dexron in it.

David 70 · 01-09-2025, 06:11 PM

unplanned tourist; I would imagine you still have the Allison trans. The Winnie brochures list yours as a 6 speed 2100 but mine as a 1000 series. I looked at mine this summer and I'm sure the tag said 2100. I think it is just 5 speeds though. Yours must have the two brake shoes in a regular drum on the tail shaft and a pawl inside the trans. They done a lot of switching around trying to make things work and the books aren't always right as to what is what.

Unplanned Tourist · 01-09-2025, 08:03 PM

Quote:

Originally Posted by David 70

unplanned tourist; I would imagine you still have the Allison trans. The Winnie brochures list yours as a 6 speed 2100 but mine as a 1000 series. I looked at mine this summer and I'm sure the tag said 2100. I think it is just 5 speeds though. Yours must have the two brake shoes in a regular drum on the tail shaft and a pawl inside the trans. They done a lot of switching around trying to make things work and the books aren't always right as to what is what.

Yes, it's a 6 speed with the manual P brake on the output of the trans and has the park pawl as well.

So happy it's that way and no APB.

David 70 · 01-10-2025, 09:16 AM

From what I could determine on my P32, the brake light is used the same way as any other car. It shows if your emergency brake is on in your car or if there is a problem with the anti-lock system etc. The auto park light is for the AAPB and shows you have a problem with it. On the W22 and 24 the brake light also shows if you are low on brake fluid in the master cylinder. My 2000 P32 did not have that feature.

Laggard · 01-11-2025, 08:49 AM

Ron disconnect APB pump motor, make up some jumper wires connect to battery connect pump wire plug circled on post 21. If the pump runs replace green / brown switch and grey switch. Grey switch is located at park actuator passenger side of the motorhome.

Once that is done can see if the APB is working, than with the APB disengaged you check for leaks.