Can't unlock my parking brake! - Page 3

musigenesis · 05-19-2022, 07:16 AM

Quote:

Originally Posted by Dbacks2k4

Possible but on all my ICs of this generation if the interlock is triggered it prevents the engine from starting, not from disengaging the parking brake. Definitely worth checking out though!!

Also, the roof hatch isn't usually wired up to the interlock circuit anyway, since an open hatch is not the same kind of safety concern as a locked emergency door is.

Scott56082 · 05-19-2022, 10:18 AM

Does this bus have a P on the shifter? If so it needs to be in Neutral to release the brake.
On some lift busses the P park has a brake interlock to go along with the lift.... To operate the lift you put it in P and the brake will engage, or you have to pull the yellow button to engage the brakes..... But the brakes will not release until the vehicle is in neutral and the lift door is closed.

ewo1 · 05-19-2022, 10:28 AM

Quote:

Originally Posted by Shortbus PA

Yeah, it's not an issue of my trying to release the parking brake without having my foot on the brake pedal.

There's no switch open the panel for the wheelchair lift, that was operated by a switch on the lift itself.

I removed the lift about six months ago and have driven the bus without a parking brake problem. The problem with the parking brake began after I removed the ceiling escape hatch and disconnected the wire that ran to it.

So, my best guess is that there's a interlock system. As I said in my original post, I've got a beeping noise now after having removed the hatch ... and the brake pressure warning light is on.

So ... I'm looking for ideas on how to rectify the interlock problem.

I found a service manual for the BE/CE - 200/300 body.
It covers busses from 2001-2015. mayabe your wiring diagram is the same or similar?

This service manual is 842 pages, too big to upload and I haven't spent the time looking thru it...

I hope you find it helpful.

link-> http://bodybuilder.navistar.com/Gene...0000003601.pdf

I also found the operators manual too! It is 6mb, too large to upload!
-> https://www.leedstransit.com/sites/l...tor-manual.pdf

Samarath · 05-31-2022, 04:30 PM

Quote:

Originally Posted by Shortbus PA

So ... I don't have air brakes on my bus (it's a 2007 IC E300) and the yellow parking brake button won't release.

This is what's happened on the bus recently that might have caused the problem:

1. I disconnected and removed my roof's escape hatch (now there's a constant beep whenever I start the engine ... would love to figure out how to stop that)

2. I've started and run the engine weekly, but the bus hasn't been driven for 4 months or more

3. I'm also getting a brake pressure warning light on the dashboard.

Any ideas on what to do would be greatly appreciated!

We just bought a 2007 IC CE200 and the cable was already cut. I was reading the operator manual today and it mentions that if you have low brake psi in both the front and rear system, then it kicks in some safety features. Once you are below 25mph you can't accel beyond that and once you set the parking brake, it can't be released until the problem has been addressed. I am newer at this than you, but that's why I was reading through my manual. I'll grab the details tonight and update you, but between interlocks and possible hydraulic issue, maybe you're able to narrow things down. I guess there is a hydraulic booster that operates your rear brakes and your main hydraulic cylinder that operates the front brakes. I maybe screwing this up, but I'll confirm when I get back to my manual.

Good luck

Shortbus PA · 05-31-2022, 04:41 PM

Thanks for your post!

I had a bus mechanic come out to look at the parking brake issue this morning and got horrible news! He said it was a bad hydraulic control unit ... which he said was going to cost $7,000 to replace.

I'm devastated. Not sure what to do, whether it's even worth fixing, whether I should cut my losses and run.

Samarath · 05-31-2022, 05:31 PM

Well, we are about to head across the country with our parking brake disabled by cutting the cable, but all of our other systems are functional and we've just been chocking the wheels when we stop. I guess I don't know if your hydraulic controller is for your service brakes or your parking brake, but I hope you're able to get around spending so much money!

ewo1 · 05-31-2022, 07:37 PM

Quote:

Originally Posted by Shortbus PA

Thanks for your post!

I had a bus mechanic come out to look at the parking brake issue this morning and got horrible news! He said it was a bad hydraulic control unit ... which he said was going to cost $7,000 to replace.

I'm devastated. Not sure what to do, whether it's even worth fixing, whether I should cut my losses and run.

$7 grand. WOW!!!!

Is this the unit you’re talking about?
https://www.vanderhaags.com/detailvi...?part=25139566

I wonder if that unit is serviceable ?

If this is the same unit…. I found this service doc that might help you figure out what to do next….
https://www.doverbrakeinc.com/downlo...ER%20BRAKE.pdf

I also found this NTHSA document that talks about service procedures.

https://static.nhtsa.gov/odi/rcl/201...0V104-0222.pdf

Good luck, keep us posted!

Shortbus PA · 05-31-2022, 07:53 PM

If the CE and BE models use the same part, that could be it.

The manual is perfect, thanks!

I'm searching now for a second (and maybe even a third) opinion from other mechanics before I make any decisions.

I've considered pushing my bus into the Susquehanna River that runs behind my house, but with the parking brake locked I can't even do that.

BamaBus · 05-31-2022, 10:11 PM

Shortbus PA, see if you have the valves sitting on the metal shelf like post #35 in this thread https://www.skoolie.net/forums/f53/p...ion-39444.html. This is under the hood just in front of the driver. If not can you post a pic of that same area to include the brake control unit?

sportyrick · 06-01-2022, 05:08 PM

You know hydroboost is run from the power steering pump also, I wonder if you could just change it over to that? It has brake fluid just like yours I assume and are laying all around the junk yards on medium duty trucks and busses. Just a thought. I know someone else with a medium duty box truck and just went through this with theirs. Everyone seems to shy away from air brakes, that is a very simple system compared to this crap. Come to think of it that 05 BB that I junked was having trouble with it's juice brake system, pheeewwwwuuu, glad it's gone.

Jolly Roger bus 223 · 06-01-2022, 07:13 PM

ok i tried to follow this post but kept getting distracted everytime i get on here from work so sorry if this is a stupid question.
are we looking at s lucas girlig brake system a hydromax system or hydro boost or waiting on the owner to respond?

cofrari · 06-02-2022, 08:18 AM

Quote:

I may have misread your initial post... is your parking brake activated by a yellow diamond-shaped knob on your dash? That would indicate air over hydraulic.

Just FYI: I have a 2008 CE300 with Hydraulic brakes and my brake release is the yellow diamond-shaped knob on the dash. So that knob alone won't allow you to differentiate between air and hydraulic.

My bus had a problem with the braking computer. Ultimately I needed to get that replaced ($4000). With that issue, when the bus detected there was a problem with the braking computer, it would also not release the parking brake. To get around that, you should have 3 main fuses in the battery compartment. One of those is for the braking computer. If you pull that fuse and leave it out for about 10-minutes, it will reset the computer. No harm in pulling all 3 since you probably don't know which one is which. Pull all 3, wait 10-minutes, then put them back in and see what happens.

Oldyeller · 06-03-2022, 10:17 AM

Quote:

Originally Posted by Shortbus PA

If the CE and BE models use the same part, that could be it.

The manual is perfect, thanks!

I'm searching now for a second (and maybe even a third) opinion from other mechanics before I make any decisions.

I've considered pushing my bus into the Susquehanna River that runs behind my house, but with the parking brake locked I can't even do that.

Imagine how screwed you'd have been if this had happened on a trip instead of in your driveway, I know it doesn't feel like it but you got lucky.

I'm sure by now you realize the mechanic quoted you high. I expect you'll do your due diligence and see what might be available used, rebuilt or maybe there are even rebuild kits that would allow you to do it yourself.

BTW, is there any question that the mechanic was correct in his diagnosis? It'd really suck if you source the part he said is bad and discover he was wrong?

Shortbus PA · 06-03-2022, 05:55 PM

IMG_4533.png

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Samarath · 06-05-2022, 10:14 AM

So you have hydraulic brakes, but the parking brake on my bus is kind of strange to me. It is actually a drive shaft brake from what I was told. A collar near the rear diff squeezes the drive shaft. There was an issue with my ce200 not disengaging the PB, so I am hoping this turns out to be a little less of a headache than it seems for you. I am looking for some hope...lol

Oldyeller · 06-05-2022, 10:44 AM

Quote:

Originally Posted by Samarath

So you have hydraulic brakes, but the parking brake on my bus is kind of strange to me. It is actually a drive shaft brake from what I was told. A collar near the rear diff squeezes the drive shaft. There was an issue with my ce200 not disengaging the PB, so I am hoping this turns out to be a little less of a headache than it seems for you. I am looking for some hope...lol

If you have what I have on my '04 CE200, t's a simple drum brake (assuming it's like mine). Mine is fully manually actuated by a cable attached to a lever beside the driver's seat. The actual parking brake drum on mine is attached to the rear of the transmission. If your parking brake control is mounted on the dash then you have what the OP has, more complex.

Just for clarity's sake here are a couple pictures of my driveshaft mounted parking brake. After seeing a number of posts about problems with the non-manual parking brakes I'm glad I have what I have.

The second picture is laying on it's side. The bottom is on the right.

BamaBus · 06-05-2022, 01:59 PM

Quote:

Originally Posted by Shortbus PA

Attachment 66029

Attachment 66030

Thanks for the pics. I saw just enough of the reservoir to determine what you have. I guess the control unit the ewo1 linked to is located somewhere else.
Did you ever repair the wiring harness that was cut with the grinder? Where was it and do you know what it led to?

Shortbus PA · 06-05-2022, 02:24 PM

Yep, I repaired the cut wiring! They were all involving the front flashers (which I'd deleted), the two fans hanging above the windshield, the power mirrors, and the destination sign lights (now all working again).

I'm not exactly sure where the unit ewo1 is ... if anyone can tell me where, I'll try to post pictures of it also.

Still waiting on more mechanics to make housecalls for additional opinions.

BamaBus · 06-05-2022, 05:35 PM

Throw yourself under the bus and check the frame rails. If its there, get a part number and take a quality photo. I would recommend to take good high resolution pictures of anything you can like the transmission, engine, and attached parts. Also tire sizes and all sections of the bus like the dash, wiring compartment, etc. Write down any part numbers and/or serial numbers. It will save time later if you are not at the bus and need to know.

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