YM187

[bigE4evr]

New Yanmar owner,new member,first post.I bought a YM187 from a individule and in the process of using the tractor noticed right side brake not working. Pulled brake cover to find previous owner had not replaced gasket and brake shoes and springs were ruined by what i assumed was water getting into houseing.After removing drum and cleaning out housing and tractor sitting a couple days i noticed seal around brake shaft leaking hyd/trans fluid.Can this seal be replaced by not cracking axle housing?Leak is not real bad and i wonder if i could leave drain plug out and still use tractor with new shoes and springs installed and not screw them up until i can do repairs?
Thanks guys bigE4evr

 

[lens12]

Seal can be removed without removing axle housing. It would be a lot simpler to replace seal while you have the brakes all ready out. If it isn't leaking much you can probably get by.

 

[roger_scotty]

The brake rust is a known problem with Yanmars. I know of several such water-related design flaws in the YM series. One is that the brake drums rust too easily - possibly from lack of ventilation, open ocean shipping, or perhaps they were assembled wet at the factory. Another water problem is that rain can run down the inside of the steering wheel mounting post where it makes its way past the seals and into the steering gearbox., rusting the bearings. The last one is rain making its way past the fuel cap/fuel gauge and into the fuel tank. It seems odd that they have such a simply-fixed design flaw, but on the other hand they don't suffer from engine and gearbox problems...and rarely from electrical. The tractor may have had the beginnings of the brake problem (pitting drums) when it was brand new. This was well enough known to be covered by warranty by US Yanmar back in the 1980s. The other two problems can be bypassed by covering the tractor when it sits out for a while....which a guy probably ought to do anyway.

For the brakes, just rebuild them completely. The parts are dear, but available. You can turn the drums till smooth (or replace as a last resort), buy new springs, take the pivots apart and clean them, don't worry about the gasket as silicon seal will do. The shoes are probably used up. What is thought to have happened is that the drums pitted on the trip across the ocean, filled with bits of shoe, and accelerated the shoe wear.

Put them right and they will last for decades.

 

[gbirky]

I have 3 yanmars which came directly from Japan to me. A YM1301D, and two YM1110D's. The one YM1110D had brake problems from the beginning which I ignored while rebuilding the engine and front axle. When I went to move the tractor after repairs (8 months later) the brakes were locked up tight. I couldn't even remove the covers! I dragged the tractor up and down the driveway with my van untill they unlocked. After disassembling, I sandblasted the drums and sanded off the glaze on the friction material of the shoes (which had plenty of material left) put new o-ring seals on the pivot shafts, reassembled with RTV to seal the covers to the tranny case. The springs even looked new, so I didn't replace them. The brakes now work extremely well, and I didn't even replace any parts!

The brakes on the YM1301D squeel when I use them, but they seem to work well. I just hope the shoes aren't all worn out - I woudn't want to have to replace the drums. The other YM1110D seems to have no brake problems at all.

Greg