Brake Failure

[Renipladlo]

All - Brought home the MH today. Cannot tell you how much the brakes are improved with the fluid flush. The copper line and improper fittings are now gone, with stainless line in its place. My coach stops as easy as the car does, none of that standing on the pedal any longer for me. I recommend all to have a brake fluid flush and inspection if your brakes squeal, squeak, or you have to push down really hard on the pedal. I should note here, that the copy of this thread made a huge influence to Cummins Coach care service writers and the techs. They all read it (which I had printed out and took with me) and it was a great help to them in the diagnosis and repair. Additionally, I took the manual for the brake units with me to assist them in the flush and fill procedure, they kept those for future maintenance.

Engineer Mike also suggested this is a procedure that needs to be performed every two years. I cannot believe how much difference it made in my coach and wish I had the selling dealer do it before taking delivery last year. FWIW the total repairs cost $1206.25 and of that the parts were 140 or so. The labor was the big factor, but there was some diagnostic stuff in there which HWH did not pick up, so I had to pay for it.

Additionally, I am a Cummins Power Club member, which shaved about 110.00 of the labor and parts bill. I also get discounts on spare parts I purchase so it is good for those as well; this was the best 20 bucks I ever spent.

[EngineerMike]

re: brake fluid replacement-
My earlier 2 year cycle recommendation is hereby retracted. Make that an annual replacement recommendation.

My thinking on this has evolved over the reading of many brake related threads here on iRV2, under the Alpine forum and the Workhorse forum. Basically it gets down to pivotal importance of brake safety, and the ease of brake fluid flush vs the breakdown of brake fluid characteristics over time. Its one of those things that the downside is way too problematic to allow economy to dictate process.

Most of the functional deterioration of brake fluid is done by 18 months. 3 quarts of Dot3 brake fluid is cheap. This is an easy DIY process that many guys have done on our cars, and it is no different on the MH except that the brakes are BIG and the distances larger. AND leaving fluid at risk of boiling due to moisture absorbed into it has much bigger consequences for those around us; we are pilots of big heavy machinery, and should take that into account.

I took the liberty of removing a bleed screw from my FR wheel end, and sending the dimensions to Dale at OEMY's Performance (Oemy who posts regularly on the Workhorse Forum). Dale has lots of great Tech Tips including #7- Bleeding Brakes; this is interesting for Alpiner's as the Workhorse brake system Dale is discussing is based on the Bosch HydroMax master cylinder and either Bosch pin-slide or Meritor Quadralic disc brakes (sound familiar?). Dale matched the Meritor bleed screw to the (I hope correct) Speed Bleeders part number, and sent me a set of 4 to try as a guinea pig. These have a check valve internally, so you crack the bleed screw open with your plastic tube attached and set to drain to a large soft drink jug, then relocate to the driver's seat & pump the pedal yourself (don't have to have the DW do it and endanger the marriage). With Speed Bleeders or with Dale's advice on other one-man methods for brake bleeding, there isn't much excuse to leave this chore undone. And of course, you can always include it with any annual service punchlist at the local service joint of your choosing if you don't want to crawl around under your motorhome for fun.

If the Speed Bleeders part is correct and works (hope to install them & do a fluid flush this weekend), Dale will have these for sale on his website (Workhorse W24 models use the Meritor disc brakes on later model Alpines). Dale already sells Speed Bleeders for the Bosch pin-slide brakes for which annual brake bleeding is dramatically more important due to the moisture vs. Bakelite-lined piston swelling issues).

[Lindenberg]

How many turns do you need to open the bleed screw on Bosch calipers when bleeding the brakes?

[Renipladlo]

EM-I am in on this. When we can get together, I will assist you if necessary in testing the parts you are getting from him.

I mostly have bleed my own brakes in the past, (accept for the Ford Crown Vic) but the car sat for 10 years, and I wanted the system checked, as I had replaced the front disc calipers. My Brake specialist pressure bleed the system, then replaced the rear wheel cylinders, and then re-bleed the system. But this was because, the car sat, and I toasted one front brake assembly. I should have bleed the system as soon as I brought the car home, but was lazy, over 300 dollars later, I learned a lesson.

Cummins Coach Care did it for me this past time, but also inspected the brake lines at the rear, and it turned out I had the copper line. So that was replaced, as well as one fitting. In the future I am going to do the bleeding myself, because I know how, and then I know it's done and I saved money.

Lindenberg - I will assume no more than a full turn, not quite that much is ok too. Remember, if the bleed fitting comes out, just put it back in finger tight and don't let the person holding down the brake pedel release until you have tightened it up with the wrench. You can also get the manual from the ACA Tech Section, and read it then you will know for sure.

[takepride]

Quick question. Earlier discussion focused on the difficulty of bleeding the Alpine's brakes since there are two bleed valves per caliper and the top one cannot be had without removing the wheels. Sounds like more than DIY work when having to pull wheels.

I did see the top bleed valve on the FR caliper. No way to get a wrench to it, unless you count just touching it with the wrench.

I'd like to do my own, and soon. Is it actually easy? Or do I need some testosterone booster shots to R&R my wheels?

[wa8yxm]

One suggestion: If you are sure that copper line was Original Equipment

Drop a letter on the NHTSA (National Highway Traffic Safety Admistration)

As someone suggested.. Prosecution should be and that is.. Well, something they do

[Beagle RC Air]

Originally Posted by takepride

Quick question. Earlier discussion focused on the difficulty of bleeding the Alpine's brakes since there are two bleed valves per caliper and the top one cannot be had without removing the wheels. Sounds like more than DIY work when having to pull wheels.

I did see the top bleed valve on the FR caliper. No way to get a wrench to it, unless you count just touching it with the wrench.

I'd like to do my own, and soon. Is it actually easy? Or do I need some testosterone booster shots to R&R my wheels?

No, it is not easy to get your wheels off, but if you have the right tools and a good understanding of how to handle the weight without hurting your back it can be done at home.
An option might be to have truck tire shop pull the wheels off at your site and come back later and put them on. They have service trucks that can take off all 6 wheels in about 10 minutes if you have your MH jacked up.

I have about $150 invested in a Makita 6906 electric 3/4" impact wrench and sockets from ebay. This wrench will not take the nuts off if they are NOT torqued over 500 ft lbs but it will do the job if they are torqued correctly.
I also carry a 3'4" T handle and a long cheater pipe for the difficult ones. (most truck tire shops torque way over the maximum, sometimes in the torque range of 700-900 ft lbs).
I pull my wheels off every summer to polish wheels, lube and check tire tread.

Look this web site over to get more of the technical details,
Solid contact - Truckers News
If you have any further questions send me an email.

[Renipladlo]

TP & All, we were considering a trip to Alaska next year. One tool I was going to take with us was a 12 ton hydraulic jack for the speicific reason cited above. To at least get it in the air. Then how do I support that kind of weight safely, and I backed away from that. Now, the brake bleed procedure again would require me to get the thing in the air, and HWH and Alpine do not recommend using the Hyd Jacks for this purpose, although I have seen many owners doing just that.
Now I'm back to getting the 12T bottle jack, and finding a jack stand that is rate as well. I am going to do my brake bleed next year, if I can figure out how to get the tires off.

[Dale777]

Beagle RC Air,

The Alpine Coach owners manual states that the lug nut torque should be 450-500 ft-lbs. How do you get the Makita 6906 to do the job when the spec in the owners manual states the maximum fastening torque is 433 ft-lbs?

See this link:
http://www.makita.com/en-us/Assets/I...nuals/6906.pdf

[Beagle RC Air]

Originally Posted by Dale777

Beagle RC Air,

The Alpine Coach owners manual states that the lug nut torque should be 450-500 ft-lbs. How do you get the Makita 6906 to do the job when the spec in the owners manual states the maximum fastening torque is 433 ft-lbs?

See this link:
http://www.makita.com/en-us/Assets/I...nuals/6906.pdf

I borrowed a Makita 6906 from a friend to test prior to purchasing one. As I stated it will NOT take off the wheel nuts if they have been put on with large 1" wrenches in tire shops. I loosened all of my wheel nuts with T handle and cheater pipe the first time around. Since then the Makita has taken the nuts off ok. Sometimes they requires the T handle but 90% will come off without.
I do test the tightness after they are all run up and then at 50 miles of driving.
Previously I spent 20 plus years as a hvy equip field mechanic and I have had lot of opportunities changing out truck, grader and loader tires alongside of the road with and w/o the right tools. My impact wrench of choice then was a IR 3/4" air instead off the I" air that was left in the shop. The IR 3/4" was not rated for 500 ft lb either but with little extra hammering it got the job done. 1" air impacts require very large air compressors and tanks and space was not available in the sevice truck.
These Makita wrenches are well built for industrial work and I am very satisfied with the one I bought for $67. The finish torque is easy enough to check if you have a bar of known lenght. Makita does make an electric 1" impact but they seldom come up on ebay.
I put jack pads down that are about 4" thick and carefully lift the whole MH up till all 6 tires are off the ground about 1". I have enough blocking so that I block under the axles if I am going to leave it up for a while.
A square point shovel makes an excellent fulcrum and lever for negotiating the tire assemble off and on. Works for me.

[EngineerMike]

Wheel removal is remarkably easy with, as Beagle says, the right tools. His idea of a square nose shovel is a good one. The nuts come off (and go on) with ease using a torque multiplier. Using a half inch x 24" torque wrench on the 3.33x net torque multiplier I only need 70-75# pull or push on the wrench to achieve 475 ft# on the lugs. Tires roll, so the only real struggle is muscling them out/in of/to the wheel well; that's where Beagles shovel would come in handy. Nice tip.

[Dale777]

Beagle RC Air,

In my previous post, I was just curious how you tighten to the required 450-500 ft-lbs of torque with the Makita 6906's maximum tightening torque of 433 ft-lbs?

I understand the difficulty of loosening lug nuts that have been over-tightened. I'm fortunate to have the X-12 Original that gives a torque multiplication of 12 to 1 (net of 10 to 1 due to friction). So I can use this to loosen almost any over-tightened lug nut and tighten to the required 450 ft-lbs using a regular torque wrench set at 45 ft-lbs.

[Beagle RC Air]

Originally Posted by Dale777

Beagle RC Air,

In my previous post, I was just curious how you tighten to the required 450-500 ft-lbs of torque with the Makita 6906's maximum tightening torque of 433 ft-lbs?

I understand the difficulty of loosening lug nuts that have been over-tightened. I'm fortunate to have the X-12 Original that gives a torque multiplication of 12 to 1 (net of 10 to 1 due to friction). So I can use this to loosen almost any over-tightened lug nut and tighten to the required 450 ft-lbs using a regular torque wrench set at 45 ft-lbs.

I find that letting the impact continue to hammer to a count of 4 after the nut stops gives me a tightness that I can verify.

[Renipladlo]

All, I have only seen the wheels off my coach once, and was not allowed to study the makeup. But I did watch another coach who had a flat tire (bad valve) and the Les Schwab person took of the covers, then the nuts which hold on the outer tire, then some inner threaded/hex nuts deals which held on the inner tire. Seemed like a good system. While I was watching, the tire person said, you should change the inner threaded/nut things after using them three times because they can stretch out!!!.

I checked e-bay for that torque wrench, and the price was way over 67 dollars. I will keep watching for one, at a price I can afford.

Now what I want to know is which brand/type of jack stand you recommend (and please don’t mention harbor freight-I will be under this thing, and most likely it’s made in china and subpar at best). I was thinking about getting one for carrying around so I don't have to use the Hydraulic Jacks (manf recommends not to use them to raise and hold the coach off the ground) so I thought I should have something which would support the axle near that tire. Maybe two of them to keep the rear end up when working under the coach. Yes, I know to block the wheels, and need to get some of those chocks you see at loading docks, made out of old tires. I think the jack stand should be rated at least 12 tons, which is 24K, and two would be 48K pounds, more than enough to keep things safe.