Burning Smell from Left Rear Wheel

[bighealeysource]

Well, been trouble shooting minor brake problems, but now have a distinct burning oil smell and high heat coming from left rear wheel. I just got back from a drive - gorgeous down here in coastal SC - and very distinct burning smell and high heat coming off that left rear wheel/hub.

I am thinking it's a possible very minor rear end oil leak that I noticed when I had the drum off, combined with having difficulty getting that brake adjusted correctly. Almost no adjustment possible as adjuster locked all the way down or out, and I am getting friction from the lining combined with that minute leak. Didn't bother fixing that when I had it apart, but looks like I should have.

Any thoughts ?
Thanks,
Mike

 

[mezy]

I doubt you would get heat from an oil leak, more chance of brake binding, does it smell a bit like cow poo.

 

[MikeAH100M]

I had the same issue and it ended up being a stuck piston on one of the cylinders that caused the brake to bind. I replaced (twice since the first Moss replacement leaked and had to return) and the problem went away. Also helped to adjust the master cylinder slightly to give some more room/play to adjust.

 

[bighealeysource]

Hey guys,
Just got the drum off with a bit of persuasion from a hammer. Not an oil leak, just binding exactly like Mike above says ! I've smelled cow poo
before, but can;t recall that smell. Just smelled like something burning which I now believe was the brake linings against the drum. Think this
goes back to the issue of fitment but will definitely check out that wheel cylinder. I'll be back !
Thanks,
Mike

 

[bighealeysource]

I was thinking about this left rear brake issue and the locked wheel cylinder really makes sense. Going to take out the old one and
install a new one from Moss and see what happens ! Hoping it is this easy.

 

[mezy]

I would check it out first to see exactly what is seized/malfunctioning. It could be anything from handbrake cable/lever, adjuster malfunction, or cylinder. Compare all components from the good side to the bad side.

Make sure that the brake shoes are fitted the correct way as they will have a leading and trailing side. Again, check against the good side,
take pictures and compare.

 

[Bob_Spidell]

You might be able to get by with a kit if the bore of the cylinder is OK (honing isn't generally recommended).

 

[bighealeysource]

AN UPDATE - turns out the wheel cylinder was completely frozen and the small piston would not move. Finally broke it lose but not moving in and out and barely could turn it around in the cylinder. A replacement part from Moss and not that old. I have had a poor experience with Moss
replacement brake parts, this less than 3 year old wheel cylinder and brake shoes with lining falling off.

I did pull the rear hub to replace the oil seal and install a new paper gasket so hopefully fixed the minor oil leak from the axle shaft.

I installed a new rear wheel cylinder ( same Moss part as bad one but that's what I had on hand ) so hoping this one lasts longer. I could fill a dictionary with swear words getting that bloody thing off due to the infamous clips that attach it. Now put everything back together
and see if my left rear brake issue is resolved. Of course get to bleed the brakes but fortunately bought a power bleeder a few years back.
All put back together and can now actually adjust that brake properly and the drum goes on easily !

Question - the brake cylinder is supposed to move slightly as part of the design function, is that correct ? How lose should it be once
installed with the clips that are attached from the back side ?

 

[BobHaskell]

Shouldn't be loose, but should move as you put on/release the parking brake.

 

[bighealeysource]

Thanks Bob, wanted to make sure I was understanding the manual right !

 

[Bob_Spidell]

Should slide 3/8" or so. Did you (lightly) grease the parts that slide?

 

[bighealeysource]

Hey y’all,
great video and all makes sense. I did not apply a small amount of grease to the opening the wheel cylinder slides in but will now !
Thanks
Mike

 

[bighealeysource]

Well,the old gal is back together, brakes bled, and everything working well. I'll bleed them again to get it as perfect as I can but just wanted to get things cleaned up and put away. Use a power bleeder so pretty easy job to do again. Even adjusted the parking brake a bit while I was at it.
Entire problem going back to an even earlier post about brake problems was that bloody frozen wheel cylinder. Thanks to all who offered their advice and even a video ( thanks Bob ). I haven't been as active on the forum as in the past but still best thing going out there.

 

[bob hughes]

I always give those cylinders a tap up and down and a little grease on the back just to make sure they are free at least once a year ( just before MOT time)



Bob

 

[Bob_Spidell]

The rear brakes allegedly have 'servo effect;' i.e. when the forward shoe engages the drum it pushes the rearward shoe, amplifying it's ability to grab. Since the cylinder moves back-and-forth it's conceivable the hard line to the cylinder could get work-hardened and eventually fracture; though I've never heard of this happening (would probably take a million miles). Still, in theory, there should be a flex line to the cylinders.