Re: MTD Yardman Transaxle Rebuild
I have worked ln brakes for over 30 years. Ask anything you want.
My '84 C10 Chevy has a mixture of braking systems.
The VIN indicates that the truck came from the factory with a 4001-5000 GVW brake system, which is the lighter duty setup.
The front has the heavier duty 1.25" rotor and wider caliper, tho the piston bore is the same as the lighter duty 1" rotor.
It also has a double diaphram vacuum booster from the HD system.
The rears are light duty 11x 2 shoes/drum w/1" bore cylinders. (the HD system uses 11.15 x 2.75" shoes/drums, but smaller 15/15" bore cyls.)
I have replaced calipers, drums,rear cylinders, master cylinder (2x) and combination valve.
Bled, rebled, rebled again, and again...........Finally doing a gravity bleed.
Original problems were:
1.pedal mushy.
2.Rear drum brakes locking up.
Gravity bleed finally helped the mushy pedal, but the rear lock-up persists.
I even put the smaller rear cylinders into the system hoping that the lower pressure would eliminate the problem. Nope...
On the theory that I may have gotten trash in the combo valve, which is SUPPOSED to prevent rear lock-uos, I have ordered another one.
In my testing I have not been able to cause the combo valve to indicate a faulty brake condition (it has a center switch for that purpose.)
I have loosened F or R bleeder screw and pushed the pedal trying to make the poppet move,and it does not.
I plan on upping the rear brakes to the larger shoes/drums, but that requires a different backing plate that is not easily found.
I have read only 1 other post from soneone who went thru the same thing, and changing out the rears finally cured his problem
Somewhere along the line someone has either changed the front brakes and spindles, or they changed the rears.
Dunno..........
What say ye,Chuck??