Atwood Surge Brake Master Cylinder

[Tenttrailer]

New to forum. Seems like the Atwood Surge Brake Master Cylinder is no longer available. What to do now? Replacing a whole new coupler/brake mechanism on an older tent trailer probably not worth the expense since it is not just a bolt on system with my hitch design. I was able to refurbish my old master cylinder and posting some photos of what the inner piston system looks like that may help others needing to do the same thing. I could still buy a new filler cap, gasket, and rubber boot for the hitch push rod on the Atwood Master Cylinder. I bought a 1997 Jayco Eagle 12FK that was in really great shape and knew the brakes needed some work, but got caught off guard not realizing Atwood was out of business so could no longer buy a new master cylinder. I have seen a video on the internet that shows how to remove this master cylinder from the hitch coupler. In summary, first disconnect the brake line from the master cylinder; remove the filler cap; four bolts on hitch coupler top and push the safety cable to underneath the coupler frame. Work master cylinder out from underneath side of coupler. My reservoir was really grungy with sludge so cleaned it out with a flat headed screw driver and a drill wire brush to polish it absolutely clean. The attached pictures show the cylinder piston components. These are held in place with an internal snap ring (eyes facing inward) at the larger end (right side in picture) of the master cylinder. The eyes on my snap ring were gone so just use a punch or flat head screw driver and knock it out of the grove then remove with pliers. From the brake line hole in the master cylinder (left side in picture) you then can push all the components out the back with a Roberston screw driver (square head) or equivalent type tool. The components from left in picture include the rubber bushing, the spring with a perforated end cap, a rubber cap the fits over the back end of spring, a piston with O-ring. The third photo shows the perforated end cap on the spring. These components were full of black grunge and make sure the perforated end cap holes are clean. I also used a fine wire drill brush and very fine sand paper to clean out the cylinder chamber since it seemed to have a thin film of hardened grunge is spots. However, be careful and make sure not to score the chamber walls. I was able to replace the O-ring on the piston but could not find anywhere to obtain the other components. Mine seemed to be okay so reused. The last two pictures show the wheel old brake back plate and the new one. This shows why annual maintenance on your wheel bearings and brake system is a good idea. I cleaned the brake lines out by blowing air through them with an air compressor, adding some clean brake fluid, and shooting more compressed air until it comes out clean. When blowing air through the lines though, cover the ends with something that will catch the grime and fluid or you will have it all over your garage walls. I hope this helps someone else who may be in the predicament I was in.

[JFlightRisk]

Welcome to the Forum from Western New York State! From an old motorhead, nice write up. I hope your m/c rebuild hold up. I do wonder, if there's another brand of m/c that's the same, or similar for some of the parts. I'm not sure if Atwood was a manufacturer, or used a rebranded unit(?) like Bendix, Wagner, or Eis.

[Tenttrailer]

Thank you JFlightRisk for your thoughts. I will check those brand names to see if they might have some similar internal master cylinder components. My trailer brakes seem to be working fine now, but it doesn't hurt to have a line on some new components just in case the old ones become less responsive than they should be.
On another thought, I noticed you have a picture of a dog with the caption '1 Spoiled Dog'. I always say 'Why have a dog if you can't spoil them'

[JFlightRisk]

You're welcome. Another good place to call, and talk to some very knowledgeable people, is etrailer. They have a line of surge brake units, and may be able to help you with what you have, or a replacement for it, if the need arises.
https://www.etrailer.com/s.aspx?qry=...Brake_Actuator

And, yes, that pooch is spoiled. He's a Pembroke Welsh Corgi, almost 6 years old. He's our 'kid', and has me trained quite well. I thought it was suppose to be the other way around, but he had other ideas about that!!

Good luck with your research on the surge.

[camperdave]

Hi After replacing the wheel brake brake insides I found the the kit to redo the master cylinder were not available.


"Dorman TM19356 kit " worked for me so far!!!.......cleaning the body of the old master cylinder is important .....I used the old cir-clip.


This may all wrong careful testing is necessary go slow test a lot


I don't know how long it will last however we have been out a few times and all seems well
If it fails or something goes wrong ill post it here... I hope this helps .......Happy Camping!!


p { margin-bottom: 0.25cm; line-height: 115% }