Hydraulic parking brake turns on while driving

[Seb1]

So, here is the issue : since I bought my skoolie in June (IC CE300 2008, hydraulic brakes), I have been experiencing my hydraulic parking brake turning on while driving. When it happens, I have to pull over quickly as it is taking me to a stop. When I pull and push the dash parking brake button couple times, then I can get back on the road with no issue until it happens again, sometime 5 to 10 min after. No warning light on dash. It has spent now 2 months at an International dealer service shop, brake lines replaced, parking brake switch on dash replaced, SAHR canister replaced. 4 TIMES, yes 4 TIMES, they told me it was fixed, but ended up with same issue 15 min everytime when I leave the dealership. They confirmed having experienced it themselves after the second occurence (so I am not completely dumb). They indicate that they are brainstorming with other dealerships, but so far they have not found the root cause.
I am at loss on what to do. This parking brake thing has so far costed me as much as the Skoolie purchase price itself, and I have not been able to travel anywhere.
Any idea/help welcome !

[UFO pilot]

Before I say anything else I am not a bus expert. However, I use duckduckgo as a search engine and sometimes I get different results than Google or others. A quick search for 2008 IC Bus recalls leads to this site and posting:
https://www.automd.com/recall/campaign_c84896/
So there is a chance your bus got this recall and the software in the ECM is causing the issue. If that is the case your mechanic should know this already and no amount of parts replacement will change what the bus computer is doing by following its software instructions.
This is only a possibility.

[Seb1]

Thanks UFO pilot, I also came across this recall several weeks back, but i ignored it because of the model year affected (2010, 2011 for CE bus model) that are later than mine (2008 CE ). However, some earlier FE bus were also subject to this recall, and reading the recall again, the wording is not so clear anymore which manufacturing years are subject to it. The description is awfully similar though so I'll bring it to the dealer's attention and we'll see what they say.

[UFO pilot]

"Navistar has notified nhtsa about a defect in certain model year 2010 and 2011 ic ce, be, and fe school buses manufactured from november 19, 2003 through february 9, 2010........"

Yep someone was not having a good day writing that description. I take it to mean any bus of the series identified manufactured between 2003 and 2010

[mmoore6856]

if they did not fix it you should get your money back.

[cadillackid]

that hydraulic brake controller has been a huge issue with IC's ever since they started using it.. I didnt realize it went as far back as 03. . Ive seen them in the 08+ busses.. the later IC BE esp had issues with it since that model was niever made with air brakes..

[Seb1]

So here is an up-date : 2 weeks ago they called me and said it was fixed after changing some additional brake lines, at no cost... I show up and they propose that I test drive the bus (what else would I do anyway by driving it home anyway ?...). and guess what ? same issue after 15 min. Brought it back there and dropped the keys. 2 weeks later, no news, so I show up today and they told me that they filled a case to Navistar and are waiting for instructions. I asked them to check if teh bus was subject to the recall that UFO Pilot brought my attention to. They checked and answer is no : all recalls this bus was subject to had been performed. I read quite a bit of documents on line related to the Wabco hydraulic brake system, and the Electronic Control Unit can trigger the parking brake to turn on if it detects conflicting info from teh service brakes system. This can be toubleshot with the Wabco diagnostics "toolbox". Anyone familiar with that ?

[Jolly Roger bus 223]

there is a big bus barn close to you near mebane/graham off of I40/85.
i stopped in there once when i was working in the area and they had know problem talking to me.
maybe drop in and ask them.
good luck

[UFO pilot]

Any updates?

And before it gets too deep check out what I found on Schoolbusfleet.com.

https://www.schoolbusfleet.com/forum...TOPIC_ID=37575

OP the issue is your bus has a very expensive and complicated brake system that appears to have, and always will have, issues.

You need to decide at what point you are throwing good money after bad.

Edit: if the shop working on the bus this whole time have been good to you at least buy them a few pizzas or something to express appreciation. I am a mechanic myself (aircraft, not bus) and it's amazing how people will blame me if I am unable to fix a sh*t design or only have sh*t parts available when either more money should have been spent on a good design in the first place, or maybe something less complicated and more robust and simple should have been chosen.

[Seb1]

Thanks for your encouraging words ! I do not know what other choice I have than to have them fix it one way or another : I have put so much effort in it. I can smell though that the brakes ECU is involved one way or another (either the ECU is dead, or input signal to the ECU is bad). I will certainly relay to them the additional ideas in the forum you kindly sent the link of. Wondering if it is possible to change the complete parking brake system to something more mechanical without all the interlocks with the service brakes. But that would probably mess up the brake ECU probably even more.

[Seb1]

I am depressed. Bus is still there. Did a test drive last month with a tech and a laptop connected, with Wabco disgnostics SW on it. Issue happened again. Nothing "abnormal" was showing on the tech laptop (which by itself was not normal). They contacted Wabco last week who said that the Hydraulic Control Unit software was outdated. It did not sound right to me, but OK, SW up-date does not cost much. They up-dated it and they went for test drive. All was good according to them. Went there for test drive with another tech and connected laptop. Same issue happened. Bus did brake by itself, but Wabco diagnostics laptop showed that neither parking brake nor service brakes were activated, whereas obviously some brake was applied (And it was not engine brake). Tech was baffled and said that he has "never seen that before". They will contact Wabco again, but they fear the complete HCU may need replacement which is 4 to 5K$.
What do you think I should do ?
1) Cut my losses , strip everything I put in there (solar, electricals, batteries, plumbing, water tanks, appliances, flooring, etc...), sell the bus for scrap, and restart with a new one ?
2) Try to sell it as is with clear disclaimer if someone feels like having the guts to continue the brakes circus ?
3) Or continue dumping $$ in this brake system, whereas I was more expecting engine or emission system breakdowns (which will come later for sure) ?
4) ...

Thanks for your opinion.

[Mountain Gnome]

I think my answer (if I were you) would depend on how much time and effort is in the build. Is this a 3-year micro-detailed perfection, or some stuff bolted on and thrown in, or somewheres in-between?
If there is not detailed perfection in the build, I would cut my losses, try to sell it for whatever, with full disclosure, and if not simply pull the stuff. Maybe pull the stuff and sell what's left of the body for $1000 or less, with disclosure. If you sell it with the conversion, you will loose more, having to buy the stuff again, because no one will pay full price for stuff used for 1 day.
Like you said, the emissions stuff will be more big $$$ down the road, if others' posts on this site are correct.

Don't mean to be mean, but pay more attention to what you buy before you throw down the cash. I'm sure you will be focusing on that after this! This site can be a great resource for you when you find something that interests you; simply post here about it and ask, and people who have experience with the problems inherent can advise you.

[Brad_SwiftFur]

I've read about this problem with other IH chassis around the age of yours. Known issue to IH, no resolution at last check. Supposedly they are looking into it.

[CHEESE_WAGON]

What do you think I should do ?
1) Cut my losses , strip everything I put in there (solar, electricals, batteries, plumbing, water tanks, appliances, flooring, etc...), sell the bus for scrap, and restart with a new one ?
2) Try to sell it as is with clear disclaimer if someone feels like having the guts to continue the brakes circus ?
3) Or continue dumping $$ in this brake system, whereas I was more expecting engine or emission system breakdowns (which will come later for sure) ?
4) ...

Thanks for your opinion.

Option 4 - swap axles and hardware for air-brake equipped units, and do the work necessary to convert to air brakes. Only way I see to permanently fix the problem. I should think any late-model Navistar 3200-4900 series truck should have the necessary parts to do such a conversion.

BUT, your bus being an '08 with the MaxxForce engine... Well, I think most people here already know what I'm going to say about that and I've had my knuckles rapped once already for simply telling the truth.

I'm also having a hard time believing that this model was not offered with air brakes. Pretty sure the bus I transported from AZ to NYS recently was a CE and it had air brakes, albeit it turned out to be a late '03 titled as an '04, with the older nose, hence perhaps some hardware differences.

I sort of think you've answered your own question though, in regards to impending future engine / emissions problems. Personally, I think this brake system is shaping up to be the modern-day Lucas-Girling.

[s2mikon]

What kind of school do you have go to to become the kind of engineer that produces some of the unmitigated disasters that we get to drive in the automotive world? I wish I had an answer to your brake problems but looking at some of the links posted here makes me wonder if this should have been sold new in the first place.

[s2mikon]

CHEESE_WAGON, I like your idea, but what kind of liability would you be incurring if you got into a vehicle crash and injured or killed someone?

[Seb1]

Option 4 : convert to air brakes :
Yes, forgot about that : Sevice Manager mentionned it as a possibility, but could be in the 5K range to do it according to him. Good point, thought I do not discard it for now.

[Seb1]

Did some monkey math this morning :
I have spent $21000 in the bus ($3800 bus + $13200 complete conversion + $4000 of failed brake repairs).

Let's say I go for options 3 or 4 (and that they work...), which would add $5000 to already spent, leading to total spent of $21000+$5000 =$26000. Maybe the residual value would be maybe $10000 ?

With option 1, I could strip $7400 max of reusable stuff, and scrap the bus. (Total loss : $13600). Then buy a new (better) bus $4000, do conversion re-using stripped stuff and add $4000 to it. Total spent $21000+$4000+$4000=$29000 + more sweat and tears. Residual value would still only be maybe $10000 ?

With option 2, sunk $21000 +buy a new bus $3800 +convert it $13200 = spent $38000. Residual value of the new bus would still be maybe $10000. To break even with options 3 or 4, I would have to be able to sell our current bus as is no less than $12000 (38000-26000), which is very unlikely.

I could still be spending $3000 on emissions related repairs in the near future with options 3 or 4 before option 1 would prove better. And that is not even counting that a new bus may come also with its load of undetected $$ issues.

Sooooo, I keep options 3 or 4 for now.... Wifey still on board

[s2mikon]

"Wifey still on board" That is the most important part of the puzzle. This does sound like the Lucas-Girling parking brake problems on steroids. Do you have a good manual on this high tech solution to a simple task system?

[Seb1]

The crazy thing is that it is actually a fairly simple system layout, but the devil resides in the Hydraulic Control Module. I am convinced that the ECU on this HCM is either faulty or receiving sketchy input signals thru poor connections. Will see next week what Wabco says.