Cleveland Brake pistons:O ring groove dimensions
Posted: Fri Oct 17, 2014 5:23 pm
I have an old set of Cleveland brake callipers for my Boredom Fighter project and since they didn't have pistons with them, when I bought them, I have turned some new pistons on my lathe. The cylinders are believed to be Cleveland part number 061-00601. The pistons are 1.500”OD & about 0.5”deep and are of a simple cylindrical form. After many attempts, I finally managed to extract this information from Parkers in the USA and don't fancy engaging with them again, to obtain dimensions for the O ring grooves.
I sized the O ring grooves using information for reciprocating rings from various websites. The O rings are a good fit, but seem excessively tight in the cylinders -too tight for me to risk pushing the pistons fully home in the cylinders, in case I can't get 'em out! I have lubricated the O rings with hydraulic fluid & this doesn't make much difference.
Could anyone who has some expertise with Cleveland brakes advise me exactly what the correct groove dimensions should be for my home made pistons and how tight a fit the assembled piston/ O ring should be? The pistons, without O rings, are a free and smooth fit in the cylinders.
I keep looking on e-bay for suitable replacement pistons, but haven't had any luck so far.
Ian
I sized the O ring grooves using information for reciprocating rings from various websites. The O rings are a good fit, but seem excessively tight in the cylinders -too tight for me to risk pushing the pistons fully home in the cylinders, in case I can't get 'em out! I have lubricated the O rings with hydraulic fluid & this doesn't make much difference.
Could anyone who has some expertise with Cleveland brakes advise me exactly what the correct groove dimensions should be for my home made pistons and how tight a fit the assembled piston/ O ring should be? The pistons, without O rings, are a free and smooth fit in the cylinders.
I keep looking on e-bay for suitable replacement pistons, but haven't had any luck so far.
Ian