Towing without surge master cylinder?

darthRudolph

New Member
Aug 8, 2022
6
IE, CA, US, Earth
When I bought the '81 Starflyer the PO said the surge brakes were there, but the master cylinder was bad. No problem, says I, I have rebuilt plenty of hydraulic things.

Yesterday that came up in the punchlist. Pull off the little cover on the back of the hitch and find the brake line just ends in a wad of tape. There is no master cylinder... And I thought it was going to be fun finding a rebuild kit for a no-longer-produced part. Good luck finding the whole part.

The little shock absorber is still in there so the whole thing isn't completely loose. But as there's no hydraulics in there to limit the travel, and it is fully capable of traveling the entire distance of the pivot.

So, the new question is this. What do I need to be aware of (other than having zero brakes) when towing a surge-brake-built coupler that has no brakes?

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Lug_Nut

Active Member
May 29, 2016
283
Mt. Wachusett area, MA
There'll be longer stopping distances (duh!),
More of a concern is the 'slide hammer' effect as the trailer slides that 1/2 inch or so forward on the coupler as the tow car slows, then slides that same distance back when the tow-er accelerates.
It's that impact / shock that could break a ball off the hitch, or a receiver off the frame.
 

MNTCamper

Super Active Member
Jun 14, 2014
1,342
MN
My 2001 Jayco has surge brakes on it that don't work. I've towed it for the last five years that way and have had no issues and that includes plenty of mountain towing out West. When I am fully loaded, my camper weighs about 2800 lbs and I tow with a minivan. First thing I would say - not knowing your tow setup or camper weight is just be aware you don't have camper brakes. Learn to downshift, which should be the case if you have brakes or not.

The one other thing that I would say, is that if you don't intend to fix it, is get the coupler welded in place in the forward position. If you don't, every time you back up, the coupler will activate and bend and it does so in such a way that you can't really unhook from the TV when it is in that position. Braking distance increases, for sure, so understand that when driving and account for it as well as downshift when appropriate (going down hills).
 

SteveP

Super Active Member
Platinum Supporting Member
May 21, 2015
2,605
There should be a locking pin hole in the slide, used to deactivate the brakes when backing up. Just put a hardened bolt through it.

As said in a previous post, look on etrailer.com for replacement MCs.
 

darthRudolph

New Member
Aug 8, 2022
6
IE, CA, US, Earth
Good news and bad news.

Good news: I finally found a part number on the side, 82540. Something similar shown on this forum here, and a breakdown diagram of similar is here.

Bad news: That is an Atwood part number. Apparently Atwood had a fairly unique design for their couplers. Also it seems they've been out of business for some time, and there are virtually no parts anywhere.

eTrailer seems to recommend replacing the entire coupler with a more modern one, as do a couple other places I looked into...

Interestingly enough, there does not appear to be a locking pin hole. I have no idea how one was originally intended to lock it out to reverse. I think I've identified a spot in the )-shaped smiley groove where I will try to stuff a bolt through and see if I can bind it up though. I tried the "sweetie, I need a welder" thing but that didn't pan out (probably/possibly because we just dropped a wad o' cash on the trailer)

Long term plan is I will eventually grind all the welds off and replace the coupler with a solid non-surge one. Then when the time comes to do a full rebuild I'll also probably replace the axle, and that will have electric brakes. Some day.
 

darthRudolph

New Member
Aug 8, 2022
6
IE, CA, US, Earth
Alrighty. I'm either a genius or a moron. Only time will tell.

I bought a 3" piece of 3/4" steel pipe (like for natural gas). Removed the little shock absorber (part 4 in diagram) from the coupler, slid the pipe over the rod, and reinstalled. Now when the coupler tries to move (to activate the non-existing brake cylinder) it gets stopped by the pipe instead. Yeah, it took a couple tries to get the perfect length. Took almost all the threaded portion off one end, so it probably ended up around 2-1/4" long.

I tried putting 1/2-13 bolts in place of the normal cross bolt (part 20), but when I torque those down it flexes the ball-holding bit (part 36) just enough that the ball won't go in. So I just reused the original bolt. I also left out one of the spacers (part 26) and stuck an extra washer on the outside to further jam the slide-e-ness and take out what little (mostly sideways) play was left after the tube mod.

The hitch for the Kia arrived from eTrailer today. I'll install it tonight, then I can figure out what the height difference is so I can pick up the right ball mount. I also hit the AAA and papered the trailer, it's actually mine now!

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Lug_Nut

Active Member
May 29, 2016
283
Mt. Wachusett area, MA
I replaced the Atwood with a Titan brand master on the Jayco we had then. The new Titan was not much more expensive than a rebuild kit for the Atwood, plus it was similar to the Titan master on my tow dolly so one spare kit would work for both.
I did have to cut some welds to get the Atwood removed, but the Titan was (nearly) a bolt-on once the Atwood stuff was excised. I had to add a 45 elbow to connect to the original brake line, but that's minimal.

Looking for my prior post with images...
 




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