W-22 Brakes went out

[Ramblin]

Coming down the mountain last week, I was on the brakes a little more than usual. Nothing drastic. When we got to the bottom, I pulled into a truck stop to fuel up and could smell hot brakes. Fueled up, got back in and pulled away from the pump island to park and go into the store. When I stepped on the brake, it went all the way to the floor. I pumped it a couple of times, and it came back to normal. Have had no problems with brakes since. Crawled under and looked at pads and discs, they looked fine. Drove the rest of my trip home (about 3 hours) with no further problems.

Obviously, had this happened while still on the mountain, it could have been an underwear fouling incident (or worse). What would have caused this behavior, and what should I do to make sure my brakes are up to par after this?

The brake recall was completed by the previous owner, and I have the documentation supporting that it was done, but a check of the VIN on the workhorse site (Thanks DriVer) says it has not been done. Is there a way for me to tell for sure if it has been done?

[dieselclacker]

Originally Posted by Ramblin

Coming down the mountain last week, I was on the brakes a little more than usual. Nothing drastic. When we got to the bottom, I pulled into a truck stop to fuel up and could smell hot brakes. Fueled up, got back in and pulled away from the pump island to park and go into the store. When I stepped on the brake, it went all the way to the floor. I pumped it a couple of times, and it came back to normal. Have had no problems with brakes since. Crawled under and looked at pads and discs, they looked fine. Drove the rest of my trip home (about 3 hours) with no further problems.

Obviously, had this happened while still on the mountain, it could have been an underwear fouling incident (or worse). What would have caused this behavior, and what should I do to make sure my brakes are up to par after this?

The brake recall was completed by the previous owner, and I have the documentation supporting that it was done, but a check of the VIN on the workhorse site (Thanks DriVer) says it has not been done. Is there a way for me to tell for sure if it has been done?

Sound like you used the brakes a little too hard and boiled the fluid. This causes air to form in the system which is compressible and causes the pedal to be mushy or go to the floor when the brakes are applied.Stopping for fuel esculates the problem, in that no air is moving past the brakes, and the fluid absorbs even more heat from the hot rotors while parked. I would bleed the brakes, or have it done, to remove any remaining air from the system. As for preventing it from happening again, proper use of the transmission to keep the speed down, along with judicious use of the brake pedal, is what I do in our rig when decending mountains or long grades. I haven't heard of any brake problems from the new calipers installed on the recent Workhorse recall.

[Sky_Boss]

Would something like this make flushing a brake fluid out a good move?

[Ramblin]

Originally Posted by dieselclacker

Sound like you used the brakes a little too hard and boiled the fluid. This causes air to form in the system which is compressible and causes the pedal to be mushy or go to the floor when the brakes are applied.Stopping for fuel esculates the problem, in that no air is moving past the brakes, and the fluid absorbs even more heat from the hot rotors while parked. I would bleed the brakes, or have it done, to remove any remaining air from the system. As for preventing it from happening again, proper use of the transmission to keep the speed down, along with judicious use of the brake pedal, is what I do in our rig when decending mountains or long grades. I haven't heard of any brake problems from the new calipers installed on the recent Workhorse recall.

Events of the day seem to support your hypothesis. After we took a little break at the store (1/2 hour or so to eat lunch) and got back on the road, everything seemed to be working as per normal. Needless to say it was a stressful drive home, because problems that appear then mysteriously resolve themselves, tend to appear again at the worst possible time.

Its time to flush and replace the brake fluid anyway. Now I have an excuse to do it.

[Perry White]

You guys ever think of down shifting and let the Trans and motor hold the speed back?

[toneumanns]

Over time brake fluid absorbs water which in turn causes problems when the brakes get hot. You definitely need to replace all your fluid in your brake system & continue to do it about every 5 years.

[gg]

The replaced calipers in the Bosch/Workhorse recall have a bright silver finish on them. Also a WH recall sticker was placed on the front engine compartment by the Brake booster assembly.

Go to the Recall info in this site and it will have the detailed info. Use the search tool.

[Ramblin]

Originally Posted by gg

The replaced calipers in the Bosch/Workhorse recall have a bright silver finish on them. Also a WH recall sticker was placed on the front engine compartment by the Brake booster assembly.

Go to the Recall info in this site and it will have the detailed info. Use the search tool.

Thanks for that information. Another iRV2 member looked up the recall information for my coach on the WH site. I can't do it myself because the original owner registered it, and I can't get WH to release it to me.

The calipers on my coach are definately bright silver in color. They look brand new. I'll look for the sticker when I get back home.

[WeatherTodd]

Originally Posted by toneumanns

Over time brake fluid absorbs water which in turn causes problems when the brakes get hot. You definitely need to replace all your fluid in your brake system & continue to do it about every 5 years.

on the W chassis its recommended to bleed at least every 2yrs.

[Ramblin]

I'll probably do the fluid flush and fill over the weekend. Anything I need to know about doing this to the W-22 brake system?

[cannon man]

if you can get some speed bleeders it makes it real easy.

[cb1000rider]

Originally Posted by Ramblin

I'll probably do the fluid flush and fill over the weekend. Anything I need to know about doing this to the W-22 brake system?

The other thing you can do is move to a synthetic fluid. There can be a substantial boiling point difference.


Back in my days of running cars at "track events" your problem - even with cars that had big brakes did occur. We'd flush the fluid, move to synthetic, and sometimes move up to a new fluid type...

[wa8yxm]

Originally Posted by athuddriver

Would something like this make flushing a brake fluid out a good move?

My suspisicion is yes.. A bit of information on brake fluid.

There are two types, The old type, used in most vehicles to this very day is "Hydroscopic" What this means is it tends to absorb moisture from the air.

When the brakes or brake lines get hot enough, this moisture (water) turns to steam, steam, unlike liquid water, is a gas, and as such can be compressed. Causing the pedals to hit the floor.

There is a new synthetic brake fluid (NOTE in this case the old and new DO NOT MIX) and I am not sure about how it reacts with moisture in the air so I can not comment on it save to say do not mix the two. I believe it is silicon based. But that is about all I know about it.

Your symptoms suggest moisture in the brake fluid, and thus flushing is a likely a good plan..

Personally.. I'm not prepared to attempt that job on my workhorse, so I can't advise you as to how to do it save to say seek professional assistance.

[WeatherTodd]

Originally Posted by Ramblin

I'll probably do the fluid flush and fill over the weekend. Anything I need to know about doing this to the W-22 brake system?

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