The Daily Yardman Thread

[Boobala]

Re: MTD Yardman Transaxle Rebuild

Goooooooooooooood Mornin Chuck ..

Goood Mornin Gang ..

Thought for 2day ..

 

[BlazNT]

Re: MTD Yardman Transaxle Rebuild

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[BlazNT]

Re: MTD Yardman Transaxle Rebuild

Morning Ted, Stayers and Newbies.

 

[Boobala]

Re: MTD Yardman Transaxle Rebuild

Hey there Ronno .... ya might consider making contact with this MEMBER here, he built these Hot-Rods himself, and he's a fantastic Machinist and a helluva nice helpful guy, you can probably get a TON of info. / help from him .......... member name = ( 1pep )

...

 

[Boobala]

Re: MTD Yardman Transaxle Rebuild

Morning Ted, Stayers and Newbies.
View attachment 38839

..

WOW Chuck your pics have improved greatly.......... :thumbsup:..:thumbsup:.. :thumbsup:..:thumbsup:

 

[Ronno6]

Re: MTD Yardman Transaxle Rebuild

From what you are saying you have too small of brakes in rear. Or too large of a booster/master cylinder. I have seen this a lot in cars and trucks where someone changed the front brakes without finishing the rear. Or your proportioning valve could be the wrong one. Do you know if your proportioning valve is adjustable? If it's not it's probably the factory one which it would make it the wrong one if the front has been changed.

I still have trouble reconciling things in my own mind.
All the combo valve knows is pressure,back pressure,and volume.
I would think that when the pressure to the rear brakes reaches a certain level relative to the fronts,
it would stop the flow to the rear and divert more to the front brakes.
Do small rear brakes lock up at a lower pressure than larger ones?

But still, as the caliper bores are the same in either system, and the caliper pistons really don't move much,I can't see how different size rear shoes/drums or booster assistance would make a difference.

I would consider plumbing an adjustable valve into the line, but my rear brakes are foe by a 1/4" line and I have yet to find a valve that size.
They pretty much all seem to be 3/16".

 

[Boobala]

Re: MTD Yardman Transaxle Rebuild

I still have trouble reconciling things in my own mind.
All the combo valve knows is pressure,back pressure,and volume.
I would think that when the pressure to the rear brakes reaches a certain level relative to the fronts,
it would stop the flow to the rear and divert more to the front brakes.
Do small rear brakes lock up at a lower pressure than larger ones?

But still, as the caliper bores are the same in either system, and the caliper pistons really don't move much,I can't see how different size rear shoes/drums or booster assistance would make a difference.

I would consider plumbing an adjustable valve into the line, but my rear brakes are foe by a 1/4" line and I have yet to find a valve that size.
They pretty much all seem to be 3/16".

Hey Ron, Did you see my earlier post ........ https://www.lawnmowerforum.com/show...nsaxle-Rebuild?p=302178&viewfull=1#post302178

 

[Ronno6]

Re: MTD Yardman Transaxle Rebuild

Hey Ron, Did you see my earlier post ........ https://www.lawnmowerforum.com/show...nsaxle-Rebuild?p=302178&viewfull=1#post302178

In the word of Rocky Balboa..."Absolutely."
May have to contact him for his opinion.
Thanks!

edit: sent him a PM

 

[BlazNT]

Re: MTD Yardman Transaxle Rebuild

I still have trouble reconciling things in my own mind.
All the combo valve knows is pressure,back pressure,and volume.
I would think that when the pressure to the rear brakes reaches a certain level relative to the fronts,
it would stop the flow to the rear and divert more to the front brakes.
Do small rear brakes lock up at a lower pressure than larger ones?

But still, as the caliper bores are the same in either system, and the caliper pistons really don't move much,I can't see how different size rear shoes/drums or booster assistance would make a difference.

I would consider plumbing an adjustable valve into the line, but my rear brakes are foe by a 1/4" line and I have yet to find a valve that size.
They pretty much all seem to be 3/16".

I will try to explain what I "think" I know about the valves. They are not valves as you would think of valves. They are holes of different sizes. Allowing different amounts of fluid to go through them. Smaller for rear brakes and larger for front brakes. 70% of the fluid/pressure to the front and 30% to rear in a balanced system. If either is larger or smaller the equation changes. The splitter in the rear does just that. Splits the pressure to each brake equally. Proportion valve, on the other hand, splits 70 30 if everything is correct. They make adjustable ones. I hope this makes sense.

 

[Ronno6]

Re: MTD Yardman Transaxle Rebuild

I will try to explain what I "think" I know about the valves. They are not valves as you would think of valves. They are holes of different sizes. Allowing different amounts of fluid to go through them. Smaller for rear brakes and larger for front brakes. 70% of the fluid/pressure to the front and 30% to rear in a balanced system. If either is larger or smaller the equation changes. The splitter in the rear does just that. Splits the pressure to each brake equally. Proportion valve, on the other hand, splits 70 30 if everything is correct. They make adjustable ones. I hope this makes sense.

I have not seen an adjustable valve for anything other than 1/8" NPT ports for 3/16" tube.
My rear tubing is 1/4"
Guess I could use a 1/4" female inverted flare to !/8" MPT fitting to adapt.
But, wouldn't that restrict the flow?
Is that what I am looking for?
Decrease in volume, or just pressure??

So, will 30% pressure lock up smaller rear brakes sooner than larger ones??

As far as booster size, how would the rest of the system (prop valve,calipers and rear cylinders) know
whether the booster was bigger of the pedal was just being pushed harder with a smaller booster?