2006 Tandem Axle 519 70LP Brake Actuator Question

[Ranger Skipper]

Is there an o-ring for the refill cap on this system? If I fill the system it will leak from what appears to be around the cap. I've looked at every parts list I can find and none show an o-ring. I've tightened it to the point I feel I'm going to strip it out. If it's an interference seal I don't know why it is leaking because the seat on the reservoir and the cap are fine. Only good thing is it will leak to a point (couple of tows) before finding a level its happy with and not leak any more. Brakes function fine.

Second owner and I've had it for six years. Can't know if the previous owner ever replaced the components but I'm considering just ordering this 47267K kit as discussed in another thread and hopefully being done with it if thats what it needs. Who knows what else might be worn or about to fail

https://www.easternmarine.com/tie-do...der-kit-47267k

Until then, any advise on how to get a good seal on the filler cap is appreciated.

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[wmitch2]

Sounds like maybe you are overfilling it. If it stops leaking at some point and the brakes work fine, then don't add any more fluid.

[Ranger Skipper]

Thank you for the reply. I would tend to agree with you but I fill it to the recommended 3/8" below the top. Having said that and after reading the servicing recommendations again it states to check the level before every tow.

#1, who does that LoL and #2, it states that it should be at least half full (never noticed this disclaimer before) so . . . perhaps I don't have a problem at all.


It's never been just half full when checking it but if the manual says thats okay then I'll just let it seek it's desired level and run with it. Thanks for making me look at the manual again

[Ranger Skipper]

Update - So putting the boat away today and noticed the master cylinder leaking like a sieve. Cleaned it all up and started pumping the actuator to see if I could start a fresh leak to see where it was coming from. The plastic fill cap has got a hair line crack aat the base of the wrench head part. I've got a couple of new ones in cart from a supplier but then I got to to second guessing things so I'm asking, should the reservoir have pressure in it? I thought the reservoir just kept the MC supplied with fluid to pressurize the brakes calipers. Is it possible the MC is bypassing internally causing the reservoir to pressurize or is this normal? The brakes work fine. Can't back up without locking out and not too long ago I locked up the axle when I had to heavy brake before hitting a rough RR crossing at 60mph.

I've looked all over the net for an answer to this question so I apologize for having to bring it up here. I've got a long out of state tow coming up in a couple of weeks and if a new cap will fix the problem thats great. I need a new one anyway. But if I need to change/replace the MC I need to get on it now and get it done.

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[RickCamilleri]

The reservoir won't have that much pressure on it. If it did brake fluid will squirt up at you. Pacific trailer has a parts diagram. I have a feeling your piston/plunger boot may have a crack in it

[Ranger Skipper]

The reservoir won't have that much pressure on it. If it did brake fluid will squirt up at you. Pacific trailer has a parts diagram. I have a feeling your piston/plunger boot may have a crack in it

I'm ordering a new MC to remove all doubt. 18 y/o trailer that I've owned for six. Don't know if the original owner ever changed or rebuilt it.

[Ranger Skipper]

Update for what it's worth and for anyone that cares

Replaced the master cylinder on the trailer with new. Bought a Motive pressure bleeder from a supplier here in town. Drilled, tapped and installed a hose nipple in the old fill cap, installed it and a screw in the vent hole with a bit of super glue to help with sealing. 10 minute bleeding procedure and done.

Another FWIW for those that have the low profile Tiedown coupler and brake setup. The correct socket size for the cap nut that you can't get a wrench on because it's recessed is 28mm. You can force a 1-1/16th socket on it but its plastic so you will round off and deform the edges. Looks like that's what the previous owner had done on mine.

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[Bob G.]

[mactlman]

Update for what it's worth and for anyone that cares

Replaced the master cylinder on the trailer with new. Bought a Motive pressure bleeder from a supplier here in town. Drilled, tapped and installed a hose nipple in the old fill cap, installed it and a screw in the vent hole with a bit of super glue to help with sealing. 10 minute bleeding procedure and done.

Another FWIW for those that have the low profile Tiedown coupler and brake setup. The correct socket size for the cap nut that you can't get a wrench on because it's recessed is 28mm. You can force a 1-1/16th socket on it but its plastic so you will round off and deform the edges. Looks like that's what the previous owner had done on mine.

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1-1/16 is a 27mm thus the issues

[Ranger Skipper]

1-1/16 is a 27mm thus the issues

Yes sir. 1-1/16th was the largest socket I had and it was too tight. Took the cap to Autozone and started checking for fit. 1-1/8 was too large. 28mm was a perfect fit. The MC had a mix of SAE and Metric hardware on it which I thought was weird. China parts assembled in USA?

[MikeF]

China parts assembled in USA?

If all the manufactures have their parts made in China, how do you not build a trailer in the USA without China parts?

Kodiak, Dexter, UFP, Tie Down Eng., etc are all made in China, as far I have seen.

If someone knows of a brake system for boat trailers with parts made in the USA, I would be very interested to know.



Good to hear you got it fixed.