I originally started a thread asking for recommendations/help on replacing a leaking front ABS valve here:
ABS Valve replacement recommendation (http://www.foreforums.com/index.php?topic=29965.0)
About a year ago when the issue first arose I went to FOT and talked with an individual in service who said something like 'yeah we've had customers with your issue before and never found a solution' and didn't seem particularly interested in pursuing a solution.
However, after a rather circuitous route around NAC I ended up back at FOT talking with James Triana and accompanying him into the shop where, in fact, they were replacing the ABS valve with a standard relay valve on another coach. At this time they don't seem concerned about DOT as they put them in MH's before it was ever required.
I set up an appointment on the spot and yesterday had the ABS valve replaced with a standard relay valve, the front ABS sensors removed and the ABS controller disabled. I spent last night at camp Foretravel and the air pressure only dropped 5 psi overnight (instead of the previous 80+ psi). Since my previous coach didn't have ABS, or even disk brakes, and I was comfortable with that I'm an even happier camper now!
Hopefully, this will show up for others in a similar predicament.
Could you post a picture of the valve?
Say BillO, I am curious, with your abs problem, were you getting the ABS Caution Light when you started up and began moving the coach, and it then would go out sometime later down the road? Mine does, and I also have an air leak that I just can't find that brings both tanks down within 24 to 36 hours.
Thanks, Mike
So Bill,
How does this system work?
It sounds like you have remove ABS brakes from your front axle?
If the wheel speed sensors are removed from the front wheels how would it know if a front wheel was locked up?
Always something new.
Mike, your big leak down could be a few things.
I found after some searching that the step slide cylinder was leaking badly and changed the set up (as others have now done) and that made a big difference.
Another place to look are the check valves on end of air tanks and the one at Air Dryer. these could be not sealing and air going backwards and out thru dryer which you would not hear. Another small leak has been found in Parking Brake controls. All easy to fix but you should determine which tank and circuit has the big leak and go from there. If you have the air operated step they can cause leaks too past O rings on cylinder shafts.
Lots of known leak points.
JohnH
John, is 5 lbs. overnight considered big?
Actually 5 PSI overnight may indicate ZERO leak if ambient temperatures dropped, that alone could account for PSI drop.
And, if it is a 5 PSI drop, that is EXCELLENT.
Like Brett said that is NOTHING!! I get about the same as in a week or 2 it usually is down to 60 ball park. I found my steps are still the main culprit and keep intending to remove cylinders and rebuild but something elso comes up more important. DW needs me to fix or do something!!! ^.^d
JohnH
Both tanks down 50 psi in 4 hours. No pressure on airbags as coach is 'blocked'.
Mike
Sorry, I didn't take any pix.
I took in this stray dog back in the summer. It's still very puppyish and friendly so I spent most of the time while they were working keeping her out of the shop and off the mechanics.
This valve did not look anything like the Wabco pix that you posted in the previous thread. It provides the same function but incorporated everything in one big "block".
My ABS light would go on a start-up but go off immediately as soon as the coach started rolling. I believe that was the normal operation for this system.
In this case the leak in the valve was obviously audible. After I had the step and step-well cover cylinders replaced the tech that did it called me over and pointed out the air flow coming out of the body of the valve. It could be heard by just sticking my head under the coach ahead of the front axle.
John,
It is a bit more than that. The complete ABS has been disabled as the remote ECU was shutdown to turn off the dash light. There is no overt way to tell if a wheel locks up other than feel.
As I wrote initially I'm not too terribly bothered my it. My last coach was heavier, had no ABS and drum brakes to boot. I drove that for 6 years without incident.
BillO,
Thanks for that information.
I have the same leak down, What did the parts cost?
Howdy from New Braunfels--Just got back from a 500 mile round trip to NAC and spoke with Braxton at FOT regarding my ABS Valve replacement. I believe our coach was the other rig being serviced recently with the same concern. Braxton mentioned the same situation arose on another late 90's coach, (maybe yours?) after ours was resolved recently. I've never ever quoted myself before, but, here's my old post:
The FT parts folks dead-ended looking for my obsolete part. Their replacement was installed, eliminating the ABS function. A call to Braxton will give you the cost of RR. (I haven't seen the bill.) Hope this helps! Our valve's photo is glued back on my old post and I am too pooped to pry it off that old post and stick it up here. G'night!
Paul,
I believe that you were likely the ones in FOT when I first went in to talk with James Triana. We ended up in the shop with Alton who said they were replacing the ABS valve with a standard valve on the coach in the first bay (nearest the parts counter).
I looked up your previous post and the picture is pretty much exactly what I had as is the number (except mine was just a number which came up as Haldex -- likely due to a merger).
For those who asked for a picture, Paul was more thorough than I and has it here:
"Stranded" at Home: Brake Valve Hanging Up (http://www.foreforums.com/index.php?topic=29752.msg253665#msg253665)
Assuming that your leak down is from the same source, the replacement valve is very reasonable -- around $60 at FOT or ~$100 from a parts supplier. Labor was a little over 4 hours, including pulling out the front wheel sensors and disabling the full ABS function in the coach (i.e. turning off the ECU).
If you are thinking of DIY make sure that you get the right TYPE valve. When I first called Haldex the tech told me informally (avoiding liability issues) to replace with a RELAY valve with a 4psi crack pressure. At FOT the mechanic was talking about a quick release valve and the service writer said they had replaced Paul's valve with a check valve. These terms are not interchangeable at all!! The actual valve they put in my coach was a relay valve.
We may have discovered the mean-time-to-failure on this valve. About 21 years or so? Mine hung up once before failure and I figured that we had snorted that bit of silage right out of the beast- but no. It let me down again.
I will get a detailed, written explanation from our manufacturer, I am sure, before I pay my bill. We can share the results of this new experiment with everyone interested at that time. Sound good?
If I disable ABS, I must be about even with the other SOB high-line coaches, right?
At one time there must have been an overhaul kit for these valves.
Like every thing else, there has to be one sitting on a back room shelf somewhere, probably a valve also!
Another item on the scavenger hunt list!
I think you're right on the last point. My previous coach was a '95 Vogue Prima Vista, which was certainly another high-line offering, with neither ABS nor disk brakes.
I suspect that you're right on both points. However, in a year of searching I could not find anyone that knew about them.
The reason that I ended up back at FOT is that someone else went there and found a referenced replacement valve. However, when it was compared to the valve on my coach the electrical connections were not compatible (old 4 prong connector versus replacement 3 prong connector). I suspect that it might have worked if electrical connection specs for both were still available. FOT did not have the specs and without those specs a conversion harness would have been just a guess and not worth the potential liability. Interestingly, Haldex makes a 4 to 3 conversion harness pigtail, but only in the opposite direction. The techs that I reached there didn't know enough about these old valves to address rewiring.
There is some scuttlebutt around NAC that some years ago FOT sold off a lot of spares inventory to another RV shop there. According to the rumor that inventory was put into containers which were never opened or sorted for contents. If the rumor is true I would not be surprised if there are some valves hiding there.
BillO...call up Aubrey Lee at MOT. 936-564-1112. He was the electrical engineer guru at FOT and is now at MOT, very glad that he was kept in the industry! A resource if on road and need some help but the electrical things were, I was told, his main area. You can check with him. Very nice fellow.
Encore had lots of decals and such, he tried to get molds from FOT but Bob told me that they were destroyed. Last I knew, some of that inventory was preserved by Bob out at a hanger, but I have not tried to trace that down. If it vital to have, call Stewart Canty at MOT, he may know as he has a hanger.
Hope this helps.....
mike
The 96 Monaco Signature had the same Meritor anti-loc discs as my 99 FT.
John D, when I had my leaking valve issue, for the rear ABS, after many phone calls about doing my own repair, was told you needed to be DOT certified in order to repair them. Fortunately FOT had one in stock that was a direct replacement for mine. I still have my old one, still deciding on what to do with it.
Not the newer ones, though ;) . Most of the Spartan-based have the Wabco 6S/6M ABS system. Not familiar with the Freightliner RV chassis specs.
Mike,
Aubrey was the fellow who brought the valve back from FOT. When the MOT tech working on my rig saw the incompatibility he went back to Aubrey and Kieth, returning with the info that both had said just forget it. That's when I went over to FOT.
I don't believe that any of the OEM's pay much attention to component systems like ABS other than to install and hook up the parts. Certainly they don't have the background/knowledge to bridge from 4 to 3 wire system connections. My guess is that the earlier system had separate grounds for each brake side and the 3 wire used a common ground, but figuring out which wire is which without Haldex/Midland specs was too much of a risk.
Michelle,
My understanding is that at some time in the past DOT set regs requiring all vehicles over a certain GVWR to have ABS. I don't know exactly when this reg was implemented, but suspect that this influenced the thinking of some shops that didn't want to touch my brake situation.
Trying to find the requirement for ABS brakes.
On the Haldex web site I found a table with ABS requirements that states any single unit ( trucks or buses, RV's not mentioned )with air brakes manufactured after March of 1998 must have ABS brakes.
If so, when did Fortravel change to a different system if parts are not available for this system? They are using something.
Is this another one of those " this system is obsolete " so it will require changing to a new system when parts are needed?
John,
A few observations.
Haldex likely listed trucks or buses as that is their focus. I suspect that the DOT reg was more general (i.e. all vehicles with air brakes over xx,xxxx lbs. must have ABS).
Foretravel appears to have gone through a number of iterations. However, even later ABS may not help. If you go back and review the original thread that I started one poster (rbark) had a later Wabco system and even he had to resort to a re-manufactured valve after a search.
Even in the regular automotive world consumer protection regs only require parts availability for 15 years. Judging from stories of other RV owners this doesn't apply to the RV industry.
Essentially, someone with a DP built after the ABS reg went into effect may run into a dilemma when it fails down the road -- invest in a new ABS (big bucks), go back to non-ABS and have a good lawyer on retainer, or send the rig to junk yard. If the coach is new enough to still have parts available and one plans to keep it, investing in spares might not be a bad idea.
The regulation as I read it states that trucks and motorcoaches with air brakes manufactured since March 1st in 1998 must have ABS. However, I am have been searching but haven't found the definitive answer, however, I haven't found one site that lists motorhomes in the same category as motorcoaches as far as a legal definition goes. My takeaway so far is that motorcoach as described in this requirement is referring to common carriers that transport passengers, in other words buses and commercial for hire vessels. I wouldn't mind confirming this, however, as the possible failure of the ABS system and its consequent disabling remains a possibility for all of us. Of course finding a substitute part that preserves the ABS function would be even better! Fortunately, not a concern for us as ours gives no indication of problems.
Don
Good faith on part of the owner, to maintain a safety system, as opposed by bad faith on part of the OEM supplier to no longer continue to supply replacement parts for a $$$$$ required safety system. ????????
While you may not find legislation saying an rv must have abs. There is slot of wording up here to the effect that if it came with abs it must still have it and work. I would imagine there is legislation along those lines where you are too. Also the liability would be huge in the event of an accident after some one removed the abs.
This is a good point though I tend to consider liability concerns overblown. That said, Texas safety inspections tend to say exactly that....it may not be required equipment,it may be optional equipment, but if it's installed it must work. I suspect this is a common requirement across many regulatory agencies.
I like ABS. Driving on ice the first time with a car with ABS and traction control really opened my eyes to the capabilities. It would be great to find a workaround to keep this system operational.
Who was the oem supplier and what part are you needing?
While it would be labour intensive it wouldn't be impossible to install a complete new system. Bendix and meritor sell systems for trailer available in many different configurations for trailers and can easily handle inputs for as many sensors and valves you would need. Even ones that are compatible with lift axles. You already have power at the original control module for it and sensor mounts are already installed so you could pull the new sensor wires with the old ones and then change out the valves to match. It would be expensive but current systems will have parts available for a long time.
Lots of thoughts and opinions! That's good.
I still have not found RV's mentioned anywhere. Also have not seen them mentioned in any list of exemptions either.
That makes me think I'm not looking in the right place.
Another question, has anyone ever had their ABS system checked during a state inspection? I never did in Washington or Texas.
ABS works. I wouldn't own a car without it.
Considering replacement for relay valve, has anyone used with success haldex part# AL430624 for a OEM part# AL45061?
The mount plate is different but does the valve work?
I have 1995 U295C foretravel motorhome.
Thanks for any input.