Once again I'm out on the road pulling 3 car's. I'm near Ocala Florida.

I've been having lot's of brake problem's. Started with spongy pedal that I couldn't get rid of. Changed everything, had dealer bleed abs unit,,still spongy pedal.

I posted about loosing trailer brake's while towing. Thought it was my brakesmart. Now I'm wondering if this has something to do with it. Everytime I thought I lost trailer brake's, I was easing into a stop holding steady, light pedal. Then I could feel the brake's give out. I really thought it was the trailer brake's though. The pedal didn't seem to go to the floor. Maybe it did though, and I just was confussed in the panic mode.

Tonight I was pulling in a weigh station, light on the pedal, and it went all the way to the floor. I gave it a pump, and got back my same spongy pedal. I thought it was the trailer brake's again at first. But this time, I know for sure the pedal went to the floor. I tried it many time's to make sure I had brake's. It seemed like I had the same crappy, spongy brake's as alway's.

I went just a couple of mile's to a truck stop, got out and looked at everything. No leaking fluid, no line's or hose's loose, nothing obviously wrong. I pushed on the pedal again, held steady presure, and it eased to the floor. Came back one time, now I have no brake's. It feel's like the first pump when your bleeding the brake's. But they won't pump up. It seem's more like a vacum thing and not an air thing. But I could be wrong.

If I had to guess I would say hydro-boost. I don't know what the heck to do. I could change that if I bought some tool's. But what if it's something else. What else could it be. If I have to put it in the shop I'm screwed. Anyone in Florida that can help out the old Broke Down Ramer Jamer.

Here's a couple of link's for some back ground.

https://www.dieseltruckresource.com/...d.php?t=205166

https://www.dieseltruckresource.com/...d.php?t=210181

 

If you get the pedal to the floor (slowly) and there is no brake fluid missing it sure sounds like the master cylinder leaking internally. - The reason:

You pump fluid by pushing the pedal. As soon as the pad is on the disk the pedal must stop- or the fluid goes elsewhere. And the master cylinder is the only place in the system that can get fluid that leaks across the piston seal back into the reservoir. Everywhere else it would go out into the air.

The hydro-boost can not be the culprit, you'd just have very high pedal effort if it went out.

HTH

AlpineRAM

 

I'm thinking master cylinder also.

*I'd also say that regular DOT approved brake fluid might not cut it. Something like a high temp racing brake fluid? Just a thought.

 

IMO this would only surface if he has got his brakes smoking hot. As long as they are "cold" - no smoke curling from the wheels- a regular DOT3 or DOT4 would work. And even if the brake fluid is boiling you can still pump the brakes and get some deceleration and the pedal stays where it is under constant pressure.

Just my 2c

AlpineRAM

 

Well this is really funny. I've been tossing and turning all night trying to figure out what it could be. Finally went to sleep. I swear I just woke up, sat straight up in bed, and said,,,"master cylinder". You guy's must have been sending me telepathic message's. Thank's for the thought wave's.

BTW. I have been running the DOT 5.1,,not DOT 5 high temp fluid. Even over time it would turn dark. What's strange is I just changed this master cylinder a few month's ago, and after many, many bleed's ($$ for 5.1 fluid) trying to get rid of the spongy pedal, the system was well flushed. I noticed this time how long the fluid was staying nice and clean. That's until I put my prodigy brake controll back on that is. In just 1 trip I've worked the truck brake's so hard from having to re-adjust the controller to low, (or get jerked to death at a stop ) the fluid is now darker than has ever been. It almost look's like tea in there. I also think that the spongy pedal had part to do with this, not getting good pedal, making me push harder.

Well I'm going to start trying to locate a master cylinder, and some tool's. Thank's again for the help. If there's anyone in the area ( Ocala Florida ) that can give me a hand, please give me a call. 618-779-3664

 

If your heading down to the Orlando area, I can give you a hand.

Tobin

 

just read thru both links and your problems are all over the place.
lets see...

1. spongy brakes all the time or intermittent?
A. air is still in system due to complicated bleeding procedure for ABS brakes
B. intermittent spongy pedal could be caused by defective brake master cylinder and/or defective ABS components or ?

2. brakesmart being part of the problems or not?
A. air introduced to system from installation.
------------

Did your problems begin immediately after install? don't think brakesmart sensor could be causing issues described.
if brakesmart is still suspected. remove from truck, then switch to another system. Jordan Ultima controller uses brake pedal position to trigger brake. so if your hydraulic brakes goes out. trailer brakes still works.

intermittent problems are the hardest to solve.

which is it? spongy all the time or intermittent?

 

sounds like either your master i done, air in the system, or you are maybe overheating the fluid(not really liekly but stil possible)

 

Thanks for all the replies. And, thank's for the call 2500. I appreciate you taking the time.

I got it fixed. The new master took care of it. By the time I bought all the this's and that's at the part's store, I spent right at $250. $60 for 1 extra night in a motel last night, and now I've missed all my drop's, so I'll be spending the week end in a motel. I also missed out on some good paying car's going back. This little break down cost me over $600.

I'm really thinking it wasn't the trailer brake's before. But I'm still going to send in the Brakesmart to get it checked out just to be safe. I don't know if I'm living wrong, causing me all the brake down's. Or maybe I'm living right because I haven't been killed by not having any brake's. I'm just lucky that I was going slow each time. What are the odd's of that.

 

glad you got her fixed!!!!

lucky no one got hurt with all the brake problems.

be sure and take the defective brake master cyl back to parts store.
they may be able to get mfg to pay flat rate hours for installation.
or not... hey it's worth a try.

 

DOT 5.1 fluid may not be your best bet. Have heard horror stories. To my knowledge, Dodge has not recomended upgrade to DOT 5 fluid. The reason was:
1. Did not have resources to test for compatiblity with seals and ABS passages used in all previous units.
2. Must completelly remove allllllllllllll (I mean all) fluid from unit.
3. Implication that air is easily absorbed, and cause poor brakes(soft Pedal). May be compounded by atmosphere pressure changes. JMHO and I saw no benefit

 

Are you talking about 5 or 5.1. The 5 is synthetic, and I heard that's what ate up the seal's. Who know's. Maybe the 5.1 is what did me in. That master was less than 6 month's old. I did talk to the place where I bought it, and they're going to give me a refund.