7/70 wheel cylinders (1 Viewer)

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Sep 28, 2010
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My 7/70 fj40 has the 7/8" bore wheel cylinders. I have a leaky cylinder again after doing a rebuild about 5 years ago. I am gonna go the same route again (clean up all the crap and install the rebuild kit) I don't feel like spending the cash right now on converting to the later model cylinders and or disc brakes. So my questions is, how much cleaning should I do? In the last I just used cleaner and wire brushed everything and then used a fine sand paper to smooth things out. Is there a cylinder hone for really get ride of the imperfections? And is a wire wheel too much on the surface. I don't wanna do too much and cause a leak. I figure it's just 5 years of use 4 of which my cruiser was my DD. Any suggestions of do's and don'ts.
 
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ImageUploadedByIH8MUD Forum1411068749.152454.jpg
 
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I have a '69 45 an I'm about to do the same. Advice to me was to clean all abrasions and black film, returning the bores to silky smooth bare metal before rekitting. In the attached pics my bores are good but the pistons need cleaning if that helps. Then there's this advice:

'I reckon a key to getting wheel cylinders to last and to be trouble free is to have good boots and ensure that there's always wet (not dried) rubber-grease under those boots to keep all the pistons sliding freely.' - Tom aka lostmarbles

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IMG_8469.jpg
 
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Gotcha. So maybe a film of grease where those boots seal up? Maybe basic grease out of a grease gun.
 
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Get a small can of high pressure brake grease. The last thing you want to do is put grease on those to keep them clean and free, just to find out that the grease you used destroyed the boots. Any brake grease will be fine. Use a hone to clean the bore and keep it soaking wet with brake fluid while you are using it. Never stop moving up and down the bore while the hone is spinning. wire wheel is fine for cleaning everything else.
 

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