Surge Brake Bleeding

oldballs · Oct 8, 2011

Having just replaced the two flexible hydraulic lines to the drum brakes, I'm having a problem bleeding the system. The master cylinder is full and the trailer emergency brake is off on this two axle rig. Shouldn't the fluid keep coming thru each bleeder valve as one goes to each one? All I get is an initial flow of about 25 cc from each wheel, then nothing more. Using the Mityvac Silverline tool, I'm pulling 25-30 inches of vacuum. What's my problem?

This thread will not self-destruck until someone accepts this mission. :laughing::laughing:

OKnewguy · Oct 9, 2011

I don't know if this will b any help or not. You are power bleeding, you might try the old fashioned way of just pumping the master cylinder. I have had 2 boat trailers now, with surge brakes, and used to have some problems, but then I figured out, that I needed to put the tongue down hill. I let it sit for a few hours and then start manual bleeding at the side that is the farthest away, and then move to the near side. What actuator are you using? I have used an atwood, and now a ufp, and on both of these there is a spot to stick a large screwdriver in and pump the master. And btw, most of the actuators, have the manual online so you can follow their specific procedure.
Good Luck, Dave

oldballs · Oct 10, 2011

Thanks, Dave. It looks like I have to take the coupler off etc. to get to the master cylinder, so as to pump the fluid out versus trying to vacuum it out. I don't know what you mean by "actuator".....I don't think there is one on my rig. It is not electric......but what do I know

It seems like the DIY life is always presenting a new experience. :licking:

Diamondpilot · Oct 10, 2011

What master cylinder/couple do you have? I do this job dozens of time as year on customers trailers. If its the type that pivots the ball on the ball simply put a ball and coupler in it and pump it up and down to bleed.

If you have the Titan style with the arm on top hooked to a chain for the e-brake simply take the 4 bolts out holding the spring steel pieces used to hold the e-brake on. Now put a piece of pipe on it and pump.

Some pics of your coupler will be helpful.

Chris

OKnewguy · Oct 10, 2011

By actuator, I mean the whole front assembly. Like this one UFP _ Actuators, or this one
Surge Brake Actuators - Atwood Mobile
Do you know which brand you have?
I have been around these quite a bit thru, my boats and friends boats, it seems very odd that you would have to disassemble anything to stroke the brakes. If you can post a pic we might be able to help.
Dave

oldballs · Oct 10, 2011

:thumbsup:As always, you guys are most helpful. It is amazing what one can learn by reading the directions. The trailer owner's manual shows that I have a Model DA 20 Actuator....Duh-h-h. Anyway, I like the part where I only have to take the e-brake cover off and pump that. Will let you know how this turns out. Someday I should get a digital camera and learn how to post pictures. Old dogs are slow to learn (or spend money) on new tricks. Thanks again.

OKnewguy · Oct 10, 2011

I looked up the manual, and it seems pretty straight forward. It looks like you use the emergency lever thing to do the pumping. Don't forget, it might help to lower the tongue to gravity take over.
Dave

oldballs · Oct 10, 2011

:thumbsup:

Thanks Dave and Chris......It's done. The trailer was up on jack stands because I had put a new deck on along with the new rubber lines....also four new tires. Anyway, the rear was raised and the tongue was lowered (but not too steep). My son came over after work and he used the big screwdriver to pump the master cylinder (thru the e-brake access) as I worked each valve. We flushed each valve three times starting at the rear then went around one more time pumping once. I also studied the Atwood site. You guys are the greatest. Thanks.......Mike