Help - no brakes!!

[benmack1]

I just bought a 37' Pace Arrow about 2 months ago.  I have done every preventative maintenance item I can think of.  I finally got a chance to go on a trip yesterday evening and 25 miles from home I came down on the brakes and the pedal goes to the floor!  I have driven the rig probably a total of 150 miles since I have owned it.  Not a hint of a problem until yesterday.  It has 41K miles and is a 1997 model 36S with a tag axel. 

More on the story.  I did have some braking power and fortunately had alot of room to woa it up from 50 mph to the end of the ramp.  The pedal was not completely soft but I certainly noticed it was not slowing as it usually does and was very squishy.  It did come back a little with pumping the pedal.  I had to keep moving to get out of the way of traffic so I slowly crawled along a secondary road and I could smell something hot.  When I got parked, I shut it down, jumped out and opened the front.  I heard a single loud click near the master cylinder if that means anything.  Could have been my imagination at that point also.  The left front and the left dual brakes were smoked.  You couldn't put your hand on the hubcap and clearly they had been locked up at some point for some distance (5 miles?).  I noticed when  came down off the freeway a few miles earlier that the rig pulled to the right when I pushed the brakes firmly (still had pedal at that time).  The tag axel on the left rear has a drum brake I think and the duals and steers have disks.  The tag on the left was not hot at all.  Only the front left and dual drive axel left sides.  All the rights seemed to only have the normal heat that a 25 mile trip on a 90 degree day would produce - not too hot.  I let it cool while the road service took 4 hours to get me and when the wrecker picked it up all brakes were released.  Those are the facts.

The wrecker driver (big semi type rig - he seemed experienced) mentioned that my brake fluid was low.  I checked it this morning and it was maybe an inch below the top of the resevoir no where near empty but definitely not full.  He mentioned that some systems will lock up when they are low on fluid.  However, I only appear to have locked up 2 of the 3 left sides and not any of the rights.  I don't know if he is correct or not.  I also read in the book that the front and rears are on different master cylinder loops but not the left and the right.  Also of note this thing has something called a hydro-booster system in the back end.  I guess this boosts the brakes in the rear somehow.  This is a ford chasis by the way.  The books also mention that this booster system has some type of connection with the power steering fluid or system.  I did notice before the failure yesterday that the steering was especially stiff or resistant.  All belts appear to be on and there appears to be PS fluid levels that are fine.

I have no idea what happened or caused the problem other than the rig has set for at least a year to 18 months before I bought it and had very little use in that time.  This problem and system is far beyond my skills in automotive repair and I am having it towed into a truck dealer (I have a great road service provider so this hasn't been that bad on the wallet - yet).  My biggest concern is that I get it fixed right and the real problem solved.  I also would like to have some idea when I go in on Monday what to expect them to say.  Anybody ever have something like this happen.  It was ironic, I had brakes lock and then really couldn't stop.  I guess I boiled the fluid and ended up with air or a vacuum in the lines and didn't have sufficient pressure to really put the binders on - at least I think.  So now why?  Thanks to any comments.

 

[King]

On my last trip, the piston in the right front caliper on my Dodge seized up.  Probably due to corrosion.  While it didn't affect the rear brakes, the rest of it was similar.  When I stopped, the right front was smoking.  The repair shop got me back on the road by replacing all front rotors, calipers and disks.  Took 2 hours and $750.  I was happy with that.
Art

 

[Just Lou]

Most likely your caliper slide pins were sticking or binding (whatever the proper word).  This is a very common problem on the older Ford chassis.  Mine is a Ford F53 with a tag as well.  Also a 1997.  Sitting for a long period of time just exacerbates the problem.

Last spring prior to my trip to Alaska, I had the same problem.  With only 27k miles on the coach.  The front and rear (drive) hubs would get extremely hot on a very short trip.  They never locked completely, just wouldn't release and would drag more as they got hotter and hotter.  I replaced all the calipers and pins @ 97$ per and found the pads were crystallized and they virtually disintegrated when removed.  They were $115 per axle set.  I also used nearly two gallons of brake fluid with the replacement and bleeding process.  I got the parts from NAPA and did the work myself. 

After you pay the huge bill for repair, expect to have to remove each wheel (about once each year) and lube the caliper slide pins.

 

[Shayne]

98 chassis here  When we bought our unit  the 1st thing I did when we got home was replace the caliphers,  We got rid of the ceramic plunger and replaced with steel plus no pads.  No more problems.  HOwever I do change pads quite often , but that's just me.

 

[John From Detroit]

Is this a used rig that has sat for a while?  I've purchased several used autos over the years, in fact a number of them are "Road Kill" (That is cars that were abandoned usually due to some minor mechinical problem, or due to the driver being otherwise occupied for oh, 3-5 years (if you know what I mean)  Without exception I found myself replacing the master cylinder fairly soon after purchase.  Sometimes I found myself replacing wheel cylinders as well.

The moral here is that vehicles are designed to be driven, unless you take some very special storage precautions several sub systems can, well, rust, or otherwise dry out or go bad, ON an RV (And on a car when present) these sub systems include Air Conditioning,  Generators (RV) Engine brakes and any shaft that turns and the seals on it (With the possible exception of the cam shaft)  Normal operation spreads lubricating oils and greases over the shafts protecting them from rust, it keeps seals moist and supple and operating properly,  Leaving a vehicle sit for six months to a year (Usuall sit time for a road kill where I live, even if the law says the towing company can dispose in 21 days) allows the brake parts to rust, as well as many other parts, when the inside of the master (or slave) brake cylinders rusts it gets rough and quickly tears up the cup washer (seal) and your pedal hits the floor and the brown smelly stuff hits your shorts (Reference an old Bill Cosby patter about always wearing clean underwear in case you are in an accident... First you say it, then you do it so why bother with clean undies)

And of course with disk brakes there are additional failure modes which others have explained already

Best option: Good brake man

 

[benmack1]

To answer John, yes this coach is a used rig (1997, Ford chasis, Pace Arrow 36S with 460 and tag axel) and it has sat for awhile.  The story is I bought this in the middle of June and drove it home about 80 miles.  No problem.  Prior to that it was owned by an older gentleman who was well into his 80's and had some health problems so the vehicle has not seen much (if any?) use over the past 18 months.  Thus his reason for selling and I really trust that there hasn't been a problem before from my dealings with him.  Based on his records, the last engine oil change was back at the end of 2004 and it only had 300 miles on it (including my trip home) during that period so that gives me a pretty good idea it has largely sat in his shed for a good 18 months.  I have only driven it twice over the 2 months I had it, both times less than 10 miles just to get used to it and to get new tires put on.  Well, the mother in-law has now left and we set out Friday night for a campground about 30 miles away and you read the above story for the rest.  I appreciate the comments from the others as well and don't really know what we'll find tomorrow, but I also was wondering if the master cylinder could be the culprit as you mentioned.  Your comments about sitting around make alot of sense and the other fact I tried to emphasize was it seems to have been two wheels that were dragging (not seized).  I have to say I am really concerned this will be an ongoing problem from some of the comments above but I hope not if I get it repaired correctly and don't let it just sit for long periods.  Also, any comments on how to make sure I keep this from happening are appreciated.  A final note, the master cylinder has two hard lines coming out are these left and right or front and rear or something else?  I noticed my pick-up master cylinder only has a single line coming out of it.

 

[Shayne]

You have another reservoir for the Rear Axle and one for the tag. 
They take brake fluid also.

 

[John From Detroit]

Ok, well 18 months sitting, then a bit of operation and another month sitting, It may well be corrosion of the master cylinder as per my suspusion.  If so then the only cure is replacement of that cylinder, same for the assorted boosters that may or may not be on your rig (per another poster who knows that chassis better than I)  Again, if there is corrosion of the cylinder the only cure is replacement of the cylinder, and following that regular use is the best prevention.  Don't let it sit for a year at a time, drive it to Quartzsite at least once a year (Arriving about the middle of January) and home.  Others here will tell you exactly where to park once you are in QZ.

Ok, just use it every camping season, that is the best preservertive (At least for brakes, tires and selected other systems,  Some systems like more frequent operation)

 

[Gary RV_Wizard]

The tag axle has separate brakes, though they are activated from the same master cylinder. That's why they didn't loclk with the others.  Sounds to me as though one or more wheels locked and the extreme heat probably vaporized (boiled) the brake fluid in the line to that wheel, causing a sympathetic failure in other wheel(s).  I'm kind of surpised it was all left side, though. Usually the fronts are paired and the rears are a separate pair, joined only at the master cylinder.