Community Forums

RJG · 05-19-2009, 08:56 PM

hello all, I am new to motorhomes and have many questions, for now I'll stick to the braking systems on the coach I just bought. On the way back from buying it and towing my ranger on a trailer., following the suggestions of the seller I found myself looking to desend a 16% grade with alot of switchbacks seams a bit crazy he sent me that way, oh well, I"m still here. anyway what I experienced was brake fade about half way down and I slightly smoked the brakes . it occurred to me at that time the trans was not holding in the gear I needed to be in (allison 6speed push button auto) I was able to pull over let the brakes cool and reset the computer fotunantly the trans saved the day, however, as a result the service brake light stays on. After getting home I pulled the tires and checked the pads there 60+% rotors are good I"m going to try to purge the brake system and install new fluid Dot 3 as suggested for the system, whats in there is the consistancy of honey perhaps a little thinner, I"m hopeing that will make the light go away. does it seam that I"m on the right track?? any suggrstions would be great, Thanks Ray..

HarveyP · 05-19-2009, 10:00 PM

Our 94 needed a new master cylinder. When I bled the brakes, the old fluid looked bad. I think you will be glad to have flushed out all the old and know that you have fresh brake fluid in the system. I don't know if that will fix the light, but it will give you peace of mind. Good luck, HarveyP

RJG · 05-20-2009, 10:31 PM

Thanks Harvey, how did you determine the master was bad? was it a warning light thing, or the brakes were not right ? I have been reading some of the posts about bleeding brake systems, and have to confess I'm a little confused with the amount of fluid some of these systems hold, I thought I may do this with around a gallon or two starting at the farthest point away form the fluid reservoir and working back. as far as draining the system I thought I would just open all bleeders and blow some air threw the reservoir, don't know if there is anything that could be hurt by doing this?? thanks for writing.. Ray..

HarveyP · 05-20-2009, 11:07 PM

We pulled out of our kids back yard and the brakes felt mushy. I stopped and checked the brake fluid in the master cylinder. It was low, and when I added more and pumped the brakes, it just ran out there. My mechanic, a thousand mile away, said it sounds like a catastrophic failure of the master cylinder. He was right! I had the brakes replaced a couple of months earlier, and he said the new brake fluid could have caused the ploblem in an old system. The replacement was easy enough that I did it by myself in suburban Washington, D.C. in 19 degree weather. Good luck, HarveyP

RJG · 06-18-2009, 09:42 PM

Hello Harvey, just an update. Changed the brake fluid last week, light is still there brakes seam to work well, the fluid was basically black, do not think it had ever been changed, getting new tires this week so I'll be able to inspect the brakes and rotors better. wondering about greasing the slides don't know if you have to pull the calipers to do that?? Thanks and take care. Ray..

HarveyP · 06-18-2009, 10:10 PM

Hi again. I don't know if you must pull calipers to grease slides. Can't offer any suggestions about the light. Going down hills bothers me much more than going up. I'm gathering info about a pacbrake. Would be nice. Good luck, HarveyP

speed racer · 06-19-2009, 07:12 AM

You didn't say what chassis you have but if it is a work horse you need to register it at Workhorse.com. There is a recall on the brake system. The reason your light is staying on might be that you burned up a antilock brake sensor. Your trans upshifts to keep you from blowing the engine up it's up to you to help keep the speed down and I recomend brakes on any thing you tow.

RJG · 06-19-2009, 09:06 PM

Hello Harvey// speed racer,
I have been thinking of an exhaust brake but that is at the bottom of the list right now $$ are getting short, tires are being installed tomorrow, and my tow bar and baseplates arrived yesterday, I"m wanting to change trans fluid to transend, and have final charge for the radiator, I have changed the belts and installed new gaskets for roof air, fixed fuel leaks thinking I"ll have to replace the pads mabey turn the rotors, I am starting to make head way though, I have set up the mh with an air compressor with extra volume tanks for my air tools. and have other various things to attend to. Speed racer this uint is a 1994 Itaska, Oshkosh chassis, cummins 5.9, allison MD 3060 PB, 14.75 rotors. well thanks you guys and take care. Ray..

hamdave · 06-21-2009, 04:01 AM

Quote:

Originally Posted by RJG

hello all, I am new to motorhomes and have many questions, for now I'll stick to the braking systems on the coach I just bought. On the way back from buying it and towing my ranger on a trailer., following the suggestions of the seller I found myself looking to desend a 16% grade with alot of switchbacks seams a bit crazy he sent me that way, oh well, I"m still here. anyway what I experienced was brake fade about half way down and I slightly smoked the brakes . it occurred to me at that time the trans was not holding in the gear I needed to be in (allison 6speed push button auto) I was able to pull over let the brakes cool and reset the computer fotunantly the trans saved the day, however, as a result the service brake light stays on. After getting home I pulled the tires and checked the pads there 60+% rotors are good I"m going to try to purge the brake system and install new fluid Dot 3 as suggested for the system, whats in there is the consistancy of honey perhaps a little thinner, I"m hopeing that will make the light go away. does it seam that I"m on the right track?? any suggrstions would be great, Thanks Ray..

You still should try to 'read' the code. Since it is a pre '96' vehicle, it is going to take some research on your unit on how to do that. On most GM products you can do that by putting a paper-clip jumper across two of the pins on the OBD connector (A & B) I think. Then the unit will emit flashes in a coded sequence that you can read. Reset can be done by disconnecting the battery for a minimum period of time . I suggesst you do some research and then proceed with that issue.
good luck

Mike Canter · 06-21-2009, 07:39 AM

When you overheated your brakes on that hill were both the front and the back brakes smoking evenly? If you drive the MH around and apply the brakes hard a few times and then pull over are the front brakes as hot as the back brakes or is one axle cold and one hot. If one axle is hot and one is cold then this would indicate a failure in the master brake cylinder.

blacktie.shooter · 06-21-2009, 09:31 AM

Quote:

Originally Posted by RJG

Hello Harvey// speed racer,
I have been thinking of an exhaust brake but that is at the bottom of the list right now $$ are getting short, tires are being installed tomorrow, and . .

I need to make sure I've got this straight, I must be missing something - you've already gone down a 16%(!) grade, tranny was not holding you back enough, you smoked your brakes - and an exhaust brake is at the bottom of your list? Somebody please help me/us out here.

RJG · 06-21-2009, 12:35 PM

Well, Ken, That somebody will have to be me, it does seem a bit odd that the exhaust brake is at the bottom of the list. However one must consider the list, that is extensive, unlike the cash flow. As far as priorities, I think I need to be sure the unit is not going to break down out on the road somewhere, on the way home from buying the coach the seller suggested I go the route back where the 16% grade was encountered, unknown to me ( I should have gone back the way I came oh well its done now) as soon as I smelt the brakes and seen a little smoke (Mike)( just the rears, the fronts were hot no smoke) I pulled over and let them cool, realizing the trans (push button was not staying in lower gears) I reset it, after that it stayed in the lower gear, after the brakes cooled I made my way dn the rest of the grade. Back to priorities, from the above posts you can see some of the things I have done so far. The brake pads and rotors are next rotors don't seam to be to bad cracks or anything guess I should turn them? the pads I thought were ok but now thinking there around 1/2 to 5/8" left or so which may be the reason the light is on if there is some solinod or something indicating the wear. now for the tow bar that I just recieved need to install baseplates and am thinking of toad brake ( Us Gear) for this system that should help considerably. the list goes on in addition to these things. so if this helps you to understand what I thinking and why, that would be good.. Dave I did try disconnecting the battery light still on, try to check the code sounds like a good thing to do if I can figure it out, as you say( more research) Mike I will try the driving and montering each wheele to see if one is any hotter than another let you know when I can , the brakes don't seam to pull or anything. the fluid I changed out was really bad, drove it to Reno yesterday for new tires the brakes worked well, ( light still on) hoping with new pads it will go away, I suppose its quite possible the master could be going bad.. I do appreiciate all your thoughts and suggestions (except ones that have a bridge) HA, HA, Thanks Ray..

Mike Canter · 06-21-2009, 01:44 PM

Ray, am I correct in saying that your braking system does not have ABS and as far as I know it is like my 1995 National Dolphin on the Oshkosh chassis with a 5.9 Cummins which was bought by Freightliner.. Mine is air over hydraulic but they also made just plain hydraulic. If no ABS system then I am pretty sure that brake warning light goes on when there is a pressure differential between the two halves of the braking system because of either a leak in half the system or a failure in the master brake cylinder. If it is like my 1995 Oshkosh chassis I don't think there are any codes to read for the brake system. Since the brake fluid was black that indicates water is or has been in the system which probably corroded the master brake cylinder so that the rubber cups inside can no longer seal under pressure, If you want I can go over to my MH tomorrow and breakout the technical manual for it but I am pretty sure I am correct. I don't see how new pads is going to fix the problem. There are no sensors in my wheels for the brakes and I have done a complete brake job myself,

RJG · 07-22-2009, 11:39 PM

All brake pads replaced, one rotor, all slides greased, much cleaning done of all brake system parts. fluid changed out and bled, service light fixed, ( proportion valve sticking on master cylinder), bearings , races, seals replaced on front end, changed over to final charge antifreeze, new belts, fuel system gone through, new tires seem to be great so far. Time to look at refer and furnace, Taking a little trip first, week or two. (Thanks, mike Canter) take care all.. Ray..