Bypass Valve

[Viv James TraX Interconnect (Pty.) Ltd]

Thanks Bob. Now I'm very happy. I'll confess to you but maybe not to the list... An elderly (even older than me) friend with a heavy right foot dropped a valve in his TC late last year making a real mess of his XPAG so I decided to fix it for him. This required a pretty complete engine job. While in there I replaced the pump gears and skimmed the lid. This was fine and I finished the job last Saturday and a really happy Barry drove off grinning like the proverbial Cheshire cat with a hot oil pressure of 62 or so at 3000rpm - really nice pressure - maybe even more than my black TC with it's newly rebuilt pump. Yesterday I received my Sacred Octagon CD and after wrestling with Acrobat etc. while looking thru it I found a 1976 diagram of the XPAG oil pump. What I saw caused me to lie awake for much of last night working out how these valves operated and wondering if I would have to remove the pump again. When I assembled the pump last Friday, I think I (actually I know I) put the bypass ball assembly in back to front. The ball and cage incorrectly seating in the engine block and the little brass end piece where the ball should seat, holding the spring down. This has effectively blocked off bypass route. The good news is that the car has a modified filter and remembering a previous thread in this list, I took some trouble to select an oil filter with a built in valve in the right place. The fact that the pressure is so good means that the ball is seating OK in the wrong place and the presence of a valve in the filter means I can sleep tonight. I think I also read somewhere that if you convert the TD/TF combined pump/filter to a modern filter with a bypass, you have to close off the original bypass. This is in effect what I have done. Having confessed, I feel better now and maybe I will copy this to the List. Viv Will someone tell me if I'm right or correct me if I am wrong: -OK TC oil pumps have 2 valves. One in the block and one in the pump top. -Yes The one in the block is a bypass valve whose purpose, I think, is to let oil thru if the filter is blocked. -Yes The one in the top is the pressure relief valve. -Yes If the filter has it's own bypass, the one in the block is redundant and could be blocked off.. -Yes. And the bypass valve is replaced each time you change the filter. But, if you block the block original bypass valve, you should make surethe filter always has a bypass valve. Some do not. Bob Bob Grunau