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Master cylinder rebuild question?

S

Speedpup

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Trying to rebuild my master cylinder on my Lull 844. I have no clue how to get it apart further than the pictures. Any tips are appreciated before I mess it up! Thanks!


[img=http://img514.imageshack.us/img514/8519/mastercylinderendviewane.th.jpg]

[img=http://img518.imageshack.us/img518/8089/mastercylinderplungeren.th.jpg]



[img=http://img294.imageshack.us/img294/7716/masterrebuild.th.jpg]




[img=http://img2.imageshack.us/img2/6190/mastercylindersideview.th.jpg]

[img=http://img2.imageshack.us/img2/8861/mastercylindercaps.th.jpg]


[img=http://img2.imageshack.us/img2/3200/mastercylindertopviewop.th.jpg]
 
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willie59

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Did you have to remove a snap ring or some form of retainer on the end where the brake rod goes in?
 
td25c

td25c

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Thats the first master cylinder I'v seen that has a threaded cap at the end of the cylinder housing.You might be able to gently drive the piston ,spring,Seals,out the threaded end.
 
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Speedpup

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ATCOEQUIP said:
Did you have to remove a snap ring or some form of retainer on the end where the brake rod goes in?
Click to expand...

retainer in the rebuild kit but I have not seen one yet:beatsme

thanks!
 
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Speedpup

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not sure if anything here helps you guys help me. Many thanks :notworthy

http://www.mico.com/products/images/34_docfile.pdf does page 14 look like mine?

Lokking at the drawings with my limited knowledge I think you may be right on pushing out from the accuator side when the threaded end is removed. I'll try that tomorrow.
 
willie59

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The pics look like a Mico straight bore master cylinder to me. If so, I believe it could come apart from either end. I don't think it's a dual stage master cyl, which has a stepped bore, because I don't see a relief valve under one of the fill caps. I'd do what wrenchbender recommended, place a phillips screwdriver in the rod end and stoke the piston in and out. It should pop apart.
 
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Muffler Bearing said:
Can you even move the piston at all? If it's really seized in there it may be a lost cause.
Click to expand...

It worked it just goes to the floor slowly then no brakes:eek:. I'll try to work on it tonight to see if it comes apart. I hope it rains early today.:D
 
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Pushed it out from the rod end and rebuilt it. So it was a straight bore like you said ATCO. Nothing looked bad in the master. Bled it on the bench and installed it. Still no brakes :( I didn't really bleed the system yet as I can't do it alone but I think I have a problem more than bleeding. When I get someone to help me I'll know.
 
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willie59

willie59

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Speedpup said:
Pushed it out from the rod end and rebuilt it. So it was a straight bore like you said ATCO. Nothing looked bad in the master. Bled it on the bench and installed it. Still no brakes :( I didn't really bleed the system yet as I can't do it alone but I think I have a problem more than bleeding. When I get someone to help me I'll know.
Click to expand...


Oh yeah, you can do it yourself, I do it all the time. You need a couple of feet of clear flexible vinyl tubing/hose, you can get it from stores like Home Depot. You need a size of tubing that will fit snug on the nipple of the bleeder screw. Open your bleed screw, stick the tubing on the nipple of the bleeder, then place the other end in a open 5 gal bucket with the end of the tubing submerged in a small amount of hyd oil (since your brakes use hyd oil). Now you just pump the brakes watching the air bubbles come through the clear tubing. When the fluid runs clear, no bubbles, close the bleeder. ;)
 
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ATCOEQUIP said:
Oh yeah, you can do it yourself, I do it all the time. You need a couple of feet of clear flexible vinyl tubing/hose, you can get it from stores like Home Depot. You need a size of tubing that will fit snug on the nipple of the bleeder screw. Open your bleed screw, stick the tubing on the nipple of the bleeder, then place the other end in a open 5 gal bucket with the end of the tubing submerged in a small amount of hyd oil (since your brakes use hyd oil). Now you just pump the brakes watching the air bubbles come through the clear tubing. When the fluid runs clear, no bubbles, close the bleeder. ;)
Click to expand...

Thanks but now I feel dumber than dumb. I do that on my race car and trucks all the time. Thanks for the refresher course. I think I can see the bleeder from the seat of the Lull.

Hope I don't have to take the drive-line brakes apart it is a PITA job.
 
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