Brake fluid leak?

[iron_city]

Hi all, we came back home after being away for a week. I saw a little trail of what I'm assuming is brake fluid coming from the drivers side rear wheel. It feels a little more oily than brake fluid typically does, but it looks like it is coming from the brake line. I wanted to ask the group what I might need to replace to stop this leak from occurring. Thank you as always for the thoughts and advice.

[92a]

I would wipe some off and smell ( or taste) it to see if if it’s gear oil or brake fluid ? Taking the drum off for a look would be the next step ? 

[steve b]

As above , but my money is on gear oil , check the breather on the axle is clear and a new hub oil seal

Steve

[Snagger]

It could be brake fluid or it could be like from inside the axle.  You really need to remove the wheel and brake drum to inspect and determine which it is, unless you have lost enough brake fluid for the reservoir level to have dropped.

Those brake slave cylinders do wear score lines and corrode and become pitted, so they do spring leaks after a few years.  Rebuild kits with new seals are available, but if the bore has any significant c damage, then honing won’t work and the whole unit needs replacing.  A nice alternative, though, would be having them line with stainless steel, which will not only resist corrosion and pitting, but also scoring far better.  You could potentially just have a small weep from the brake pipe into the slave, though, and it could need a new pipe along the axle or just need the Union tightening up a tad. 🤞

If it’s diff oil, then you need a new hub seal and possibly a new stub axle if the “seal land” (the area of the stub axle that the seal runs on) is pitted or grooved.  Depending on the cost of getting a new stub axle out there, it may be cheaper to have a local engineer turn down and then sleeve the stub axle to give a new seal land.  There is a chance, though, that it is just the paper gaskets between the main axle tub flange, the brake back plate and the stub axle bolt flange allowing oil through that joint, in which case, you need to remove the hub, stub axle and back p,ate, clean it all up, and refit either with new gaskets or RTV sealant, so a cheap but moderately time consuming job (a day for someone familiar, a weekend for a novice with the right tools and good guidance).

 

 

[iron_city]

per @steve b's comment, I checked the breather and it was clogged. So I opened up the breather again and took it for a test drive and so far so good, leaks seems to have gone away. So looks like it was axel fluid after all. I also checked the oil level in the differential and it is still good. Thank you all again for the guidance on this.

[simonpelly]

Good diagnosis with a great (simple/cheap) outcome. Certainly worth adding to the regular check list 👍

Edited 7 hours ago by simonpelly

[iron_city]

so true @simonpelly. I was really happy to see that the breather was clogged, and hoping that was indeed the issue. I'll take a look at the front axel breather tonight.

[steve b]

Good news indeed. There are also two breather tubes at the back of the engine , one each for gearbox and transfer box for future ref. , obviously if there are no trans leaks then they should be ok - the tunnel needs to come out to check the gearbox fitting but the T/box one should be reachable under the centre seat. 

edit to add : the drums do need to come off to clean residual oil from everything and to check the shoes are not contaminated

Steve

 

Edited 6 hours ago by steve b

[iron_city]

thank you @steve b, I'll clean out the drums as well