Prevost PASS

[Fratto]

Good Morning. I have not had an opportunity to use PASS since they made some changes to how they operate ... until a couple of days ago. Here is an update on my recent experience.

Leaving Santa Fe going north I got a 165 deg over temp alarm on the drivers tag tire. Pulled off and confirmed with IR gun. Long story short I finally took temps for the brake caliper and it was over 300. I called PASS and through the tech, Cory, confirmed that we would limp into a casino in Espanola.

During the first call to PASS the admin handler told me that they could charge a card for a $2,000 deposit and manage the case or they could give me a list of local companies that could remove the wheel and confirm status of caliper. Since it was after hours, we agreed to call back in the AM once we were at the casino and have then start a search for a local company and decide who was going to manage this.

I called first thing and got another handler. She informed me that the "case fee" would be $65 (no mention of this on the first call). She also said that they could manage it for $2,000 deposit. I asked her to find me some vendors (she said this had to be done by someone in dispatch) and when she called back we would decide who would mange the effort.

10:30 AM and still no news. Called back and got the first handler who informed me that the case was closed! After a painfully long conversation we finally came to an understanding that they would give me a list of vendors without paying the $2,000 deposit. If I chose to pay the deposit, they would call the vendor, manage him and follow up on completion. Given the communication issues so far, I declined the deposit. She immediately looked up vendors and gave me a list of 6 or so (no dispatch required!). I have no idea why that could not have happened the evening before. They did not do any research, just looked in their computer list of approved vendors near Santa Fe.

I called all of the vendors on the list and none of them could help me. They either did not work on buses, were way to far away or just wanted stupid money to just come out and look ... like $1,000!

Fortunately, one of the vendors sent me to another local, who in turn sent me to another local. That gentleman came out later that evening and we re-solved the issue for $600.

If I had let PASS manage this, I would still be sitting there and paying many times that amount.

So, I am glad that PASS had a list of useless vendors that eventually led me to a fantastic guy but disappointed in their new way of doing business. That said, if you can get past the handlers to a tech (Cory in this case), they are still very helpful.

By the way if you are anywhere near Santa Fe and need help, call Gerardo at Red Line 505-720-2439. He is one fantastic human. The other option is Ernie at Clark and Sons 505-471-0022, who introduced me to Gerardo and is also a great guy.

[PrevostNewbie]

What was the problem they fixed for 600.00?

[truxton]

Prevost Pass operated as a link between you and a authorized vendor who could get you fixed in different places around the country. What happened is people took advantage of that and would not pay the authorized shops therefore hooking Prevost for the bill.
Enough is enough and now your charged a fee upfront and reimbursed for any lesser charge.

It's always a few that do the damage.

Later
bv

[Fratto]

You are right Bernie. BTW, I was not trying to complain or be ungrateful, rather I was trying to effectively communicate what the current program is capable of doing and its limitations based on this recent experience. I have no problem giving them some money up front if I felt that the admin side would have managed the process well.
Again, the techs are and always have been excellent and a pleasure to work with.

Mike: Unfortunately this is one of those times where the problem was not immediately apparent. The first time that I got the 165 deg tire warning on the drivers tag, I pulled over and confirmed the temp with an IR gun. While comparing to other tires and thinking through options, it cooled off some and we got back on the road. Not long after the alarm went off again and we were lucky to have another spot to pull over. This time I compared temps of the other rotors and calipers and figured out that the drivers tag was in the 300+ range and the others in the 200 or lower range. That is when we called PASS. Believing that the most likely culprit was a sticking caliper, I hit the brakes hard several times to see if by chance it would free it up if it was dragging. After Cory (tech) and I agreed that we would drive slowly to the nearest casino, the tire temp never went over 140...was it dragging, did I get lucky and break it loose...I don't know. Even so, it seemed prudent to pull the wheel and inspect the rotor and caliper. During that exercise, we found that the caliper was moving well on the pins however, the upper half of the anti-squeal spring on the inside pad was gone. Could that have broke and temporarily bound up the caliper? Maybe but there were no witness marks. We reset the slack adjuster which seemed too tight and then Gerardo went to the passenger tag and found that its slack adjuster was set very loose so he adjusted that as well. We went through 10 or more applications of the service brakes and parking brake and the caliper performed properly every time. Gerardo wondered if the drivers tag was doing way more work than the passenger and that may have contributed to the issue. I really don't think so though. The first alarm was on the heels of retarder and brake use on the long down hills north of Santa Fe but the second alarm happened without those issues. So, unfortunately the issue may or may not still be there waiting to raise it ugly head again. That said, there are many stop lights and some good grades between Espanola and Taos and she performed flawlessly on that drive. We are going to Michigan for Busapalooza in September and will likely stop by Nashville for a few things and get them to review this as well.

Side note: I did observe that if you are parked with the engine running, the heat from the muffler and retarder can significantly affect the drivers tag tire temperature. Not an issue, but fun to know.

[PrevostNewbie]

Got it. Your bus has manual slack adjusters?

[billybeaver]

Mark:

Here is a copy of a post I made a while back. For what it is worth.

I’ll give you my experience thinking it is likely similar to yours. Everything here worth just what it costs. I have a 2000 chassis and I suspect we have the same KB SB7 series brakes. My coach has 120k miles.
About 2 years ago suddenly noted very high temp on pressure pro at the left front. Stopped and not smoking but couldn’t put your hand on that wheel but could with all the others. Can’t remember the exact temp. Pursued skillful neglect and let things cool and then pulled wheel. Brake still hot but could spin wheel and brake rotor and things all looked good. Went on with trip with no further problems.
About 6 months ago on a trip first noted a bit of increase on turbo boost on level ground indicated on my digital read out. Just watched but not long thereafter, high temp on left front. By the time I got off to stop, smoking. Same procedure. Cooled, pulled wheel and nothing. Went on and completed 3000 mile uneventfully.
As engineers, you and I have a hard time with coincidences so began digging into what is going on. Asked guys at WPB and got the shrug. Sent a note to KB tech support and got crickets. Called Kevin Laughlin and he suggested I read the service manual for my coach and follow the test procedure for the proper caliper puck adjustment and function of the auto pad clearance adjuster. Which I had already done several times and was always normal. Thanks Kevin. Took a flyer and called Prevost Pass. Got a guy who I won’t name (because see below) and he knew immediately what I was talking about. Said a well known problem and referred to as the “hot corner”. Occurs intermittently without warning and could be as much as 10k between episodes. He said the really unhappy folks were the commercial guys because the couple of hour cooling before proceeding was costing them money. Just a pain in the ass for us RV folks. He noted they put on as many miles in a month as we do in a year. He said Prevost and KB familiar with the issue and it is a malfunction of the auto adjuster. I asked about replacing the adjuster and he said he can’t say that (I suspect liability) and the standard recommendation is new caliper which was upgraded in 2014 to the SN7 and apparently has solved the problem since recurrent complaints went away.
I get that there is a lot of “I know nuttin’” going on here because of the potential liability involved and wonder if some the coach fires we hear about could be the hot corner gone to extremes. Once it gets hot enough to ignite the tire, school is out. I doubt KB or Prevost is anxious to replace all the SB7s that are out there or pay off for a burned bus so quiet has been the word.
So anyway, I replaced the left front SB7 with a SN7 to the tune of $600 or so. Warning: you have to request new bolts to attach it to the carrier. The sales people don’t realize that the SN7 takes the same size bolts but they have gone from a coarse thread to a fine thread. The old bolts are obviously worthless.
I have run it a few test runs and everything seems ok. Long trip coming up mid May. Tore old caliper apart like any good engineer would do. Only thing I noted is the chain that rotates the auto adjuster is very loose and pics of the SN7 show very little slack in that chain. I wonder if it could have been wearing and slipping a cog every so often and getting the puck moved out more and thus the pad plastered onto the rotor? Then when we stop, the brakes have again worked and moved the chain and all looks well. A truly random event. A perfect storm.
So there you have it. I guess only time will tell if it works out. I must say the guy I got on Prevost Pass sure seemed to know what he was talking about so I am optimistic.
BTW: My friend, Dean Juth, from Grand Rapids, MI has had a similar problem. Maybe we should start a club!

I haven't had any hint of trouble since replacing the caliper. MAB
Let me know if you have questions or I provide further info. Mike

[Fratto]

Thanks MAB that’s very helpful. I’ll see what they say in Nashville in September.

[Ck2hans]

Considering your past experience with high break temps what would you suggest for setting an early warning temperature alert on a tire pressure monitoring system?
Chuck

[billybeaver]

Chuck:
I realize your question isn't for me but I will chime in with my two cents anyway. I think the thing to watch for is a tire temp that is inconsistent with all the others to a significant degree. Or in my second experience a turbo level inconsistent with where it usually runs because of drag. But then, I am more than a bit anal about data as I drive. All the fun of OCD.

Mark:
That caliper isn't that hard to replace BUT heavy. Had to have my grandson help get it into place. Suspect the replacement exercise will be near and dear to Prevo$t Na$hville. The thing that spooked me was there being no residual signs of anything amiss with that hot caliper since I usually try to track down some diagnostic signs before throwing money at something.
MAB

[drivfour]

I had the exact same experience on front right brake. Called pass and got the same "hot corner" answer. I got under and loosened the slack adjuster and did not have a problem returning home.
I took the caliper apart and observed the "loose chain" as I had discussed this issue with another forum member who noted the slack chain as well. I put in new pins but did not think that was the root of the problem. I do not think an upgraded caliper was suggested. I dont know the details of the differences between new and old calipers, but it would be great if Prevost just happened to create a auto adjust update kit.

[billybeaver]

John:

Welcome to the club. The club seems to be overpopulated with engineers! MAB

[Fratto]

For now I am using the TST default high temp alarm set point. I believe that is 158 degrees and I will likely leave it as is. The tags always run warmer than the other tires so you really can only compare them to each other and take into account that one is usually in the shade and the other in full sun.

I will definitely watch them a little closer on the way home.

Three cheers for the TST system. Saved my bacon this time for sure.

I do not have my own building so replacing the caliper on my own is not an option.

[Fratto]

BTW, you could tell that the rotor had been hot but it did not appear that any real damage was done or that the rotor needed to be replaced. So if we are wanting an alarm set point that will "protect" equipment, then the default 158 seem to have done its job.

[Ck2hans]

Have noticed the inside duals run a bit hotter particularly the passengers side. Drivers side is usually 8-10 deg hotter than the outside and passenger inside is usually 10-12 deg hotter
Any body else seeing this?
Chuck

[PrevostNewbie]

I have only heard of folks using them for troubleshooting issues. I had no idea they would manage the entire process if you have an emergency.

[Fratto]

Chuck, I normally pay attention to the tire pressures more than the temperatures but yes, my inner duals normally run warmer than the outside. Other than one side being being in the sun more than the other I don’t know that I’ve noticed the passenger side running warmer. On the way home from Taos middle August I will certainly pay more attention to the temperatures and let you know.