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I have an MTD Yard Machines 13AM772F000 with a 38" deck (model 738), 2009 model I think. When I disengage the PTO, the right-hand blade stops but the left continues to free-wheel. Both brake pads are good. The left brake assembly is free to move but there appears to be no mechanism to cause it to engage the pulley. There is no spring on that side as there is on the right. My deck is the one illustrated on page 22 of parts manual 769-04344 (January 28, 2009). I have attached a copy of that page. Any ideas will be greatly appreciated.

Larry

http://www.mtdproducts.com/equipmen...Code=05&modelNumber=13am772f000&serialNumber=

inspect deck belt, idler pulleys, & all hardware for wear, check 3/8" bolt item 10 for wear & sloppy play at deck brake arm

mechanic mark said:

http://www.mtdproducts.com/equipmen...Code=05&modelNumber=13am772f000&serialNumber=

inspect deck belt, idler pulleys, & all hardware for wear, check 3/8" bolt item 10 for wear & sloppy play at deck brake arm

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Thank you Mark for your suggestions. There is no slop at the brake arm pivot bolt. Respectfully, the belt and pulleys have no bearing on my situation. When the PTO is disengaged the left brake pad is about an inch away from the pulley. There simply is nothing to pull the left brake arm toward the pulley. I thought at first that maybe the brake control rod (item #32) was supposed to do it when the right-hand brake is engaged by its spring, but now I think its sole function is to release the right brake when the PTO is engaged. It seems like there should be a spring attached to the left brake arm, like on earlier models of this mower and like on the right brake. Just out of curiosity, what does the item #22 spring attach to?

Larry

items 3 & 11 in the illustrated parts that i posted will show where to attach spring, right hand column is barely showing," view options", just click on it, then accept & download from bottom left of screen, it shows spring as item 27, also spring 28 attaches to parts 14 & 11 in diagram.

http://www.mtdproducts.com/equipmen...Code=05&modelNumber=13am772f000&serialNumber=

mechanic mark said:

items 3 & 11 in the illustrated parts that i posted will show where to attach spring, right hand column is barely showing," view options", just click on it, then accept & download from bottom left of screen, it shows spring as item 27, also spring 28 attaches to parts 14 & 11 in diagram.

http://www.mtdproducts.com/equipmen...Code=05&modelNumber=13am772f000&serialNumber=

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I'm a little confused. The link you gave lists several manuals, including two parts manuals. The one that fits my deck is 769-04344, and there is no spring #28.??

Daddyo said:

I'm a little confused. The link you gave lists several manuals, including two parts manuals. The one that fits my deck is 769-04344, and there is no spring #28.??

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No response yet?

Circled in red. Spring part number 732-04287

Daddyo said:

View attachment 30146I have an MTD Yard Machines 13AM772F000 with a 38" deck (model 738), 2009 model I think. When I disengage the PTO, the right-hand blade stops but the left continues to free-wheel. Both brake pads are good. The left brake assembly is free to move but there appears to be no mechanism to cause it to engage the pulley. There is no spring on that side as there is on the right. My deck is the one illustrated on page 22 of parts manual 769-04344 (January 28, 2009). I have attached a copy of that page. Any ideas will be greatly appreciated.

Larry

Click to expand...

On your diagram #32 is what connects from right side brake to left side brake.

BlazNT said:

On your diagram #32 is what connects from right side brake to left side brake.

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Thank you BlazNT. Yes I realize that, but it does not engage the left brake. All it does is disengage the right brake when the PTO is engaged. It hooks into a slot on the left brake arm that allows the left brake arm to move freely when the PTO is disengaged.

If you manually move the right break over further away from the breaking point doesn't move the left brake out of the way? If it does in the PTO engagement needs to be adjusted.

BlazNT said:

If you manually move the right break over further away from the breaking point doesn't move the left brake out of the way? If it does in the PTO engagement needs to be adjusted.

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While I truly appreciate your attempts to help me, PTO adjustment is not the answer. I don't know what is, but it's not that. When the PTO engages, the big spring at the end of the PTO cable pulls the left blade brake arm to move the brake away from the pulley, which also disengages the right brake by way of item #32 brake control rod. When the PTO is disengaged that big spring is relaxed, allowing the right brake to be pulled toward the pulley by its spring. The problem is that there's nothing to pull the left brake toward its pulley. Again I ask, what does the item #22 spring attach to? I can't identify that spring anywhere on my deck, which leads me to believe that it's missing and that may be what's wrong.

OK,

The brakes are joined together by the rod #32
So when 1 moves the other moves
The spring #23 pulls the right pad tight against the rod # 32.
When plate #2 rotates counterclockwise the brake pad( which should be on the back of plate # 2) gets pushed into the left pulley .
the force is supplied by spring # 22 which will either fit on the bottom of bolt # 6 or in one of the holes in plate 2 between bolt # 6 and the pivot bolt # 10 and a hole in the front of the deck.
OR to put it another way, spring # 22 pulls foreward.
In the diagram it looks like it pulls back

When you engage the PTO you pull against spring # 22 which sets the tension of the deck belt.

bertsmobile1 said:

OK,

The brakes are joined together by the rod #32
So when 1 moves the other moves
The spring #23 pulls the right pad tight against the rod # 32.
When plate #2 rotates counterclockwise the brake pad( which should be on the back of plate # 2) gets pushed into the left pulley .
the force is supplied by spring # 22 which will either fit on the bottom of bolt # 6 or in one of the holes in plate 2 between bolt # 6 and the pivot bolt # 10 and a hole in the front of the deck.
OR to put it another way, spring # 22 pulls foreward.
In the diagram it looks like it pulls back

When you engage the PTO you pull against spring # 22 which sets the tension of the deck belt.

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Thank you, thank you, thank you! Your explanation fits exactly with what I'm seeing and backs up my thoughts perfectly! Now all I have to do is get a #22 spring and find a place to hook it. YOU ROCK! :thumbsup:

Daddyo said:

Thank you, thank you, thank you! Your explanation fits exactly with what I'm seeing and backs up my thoughts perfectly! Now all I have to do is get a #22 spring and find a place to hook it. YOU ROCK! :thumbsup:

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Having just put my 38 in deck back together - replacing both spindle assemblies and pulleys, and finding how to put spring #23 back together, (see another post with pictures) We installed the deck and found virtually the same problem which started this thread. i.e. The brake pad did NOT engage the left pulley to stop the blade from spinning when the mower deck was disengaged. - - - See parts manual model series 700, page 26-27. The spring # 22 was installed, having never having been taken off, so one end is attached to plate #2, through a small hole right near the left brake pad which is on #2, and then the other end of this spring is attached to the top hole of plate #4. My spring was so attached as I described above. However - - - the spring was NOT pulling the brake pad all the way back to engage the left spindle pulley. We found that it appeared that plate #2 was binding somewhat. We lubed with WD40 and it helped, but still the spring was not pulling the brake pad all the way in. We then stretched the spring #22 to engage to the 2nd inside top hole on plate #4 which helped, but did not completely cure the problem of the Left brake pad engaging with the Left spindle pulley. We exercised the engage lever a number of times and it started to set the brake shoe into the left spindle pulley. As it is working that way now, I expect that I will have to replace spring #22 which seems to have become weak, as well as in the near future also pull and lube the Pivot bolt #10 on which the plate #2 rotates. ---- Now that I have everyone thoroughly confused, ...These two pictures of the brake spring #22 was copied from an youtube video .