MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - TD/YA oil pump internals

Can anyone help me with this small detail regarding the pressure-relief valve assembly in the cap of the oil pump: the "guide" which locates in the hole at the base of the cap,has 3 equidistant holes in its side wall. Inside the guide is the spring and steel ball. My question is does the guide need to be inserted with one of its holes lining up with the hole cross-drilled in the cap, to ensure oil flow - or does the guide rotate in operation, and thus the 3 holes automatically ensure oil passage? I suspect the latter, because of the existence of the 3 equidistant holes, but before final assembly I seek confirmation from someone with more experience. If I knew how to, I would attach a photo for clarity! By the way, what size is the steel ball supposed to be? - it looks like about 31/64ths, but will a half-inch do the job?? All help appreciated. Thank you - John.
J.P. Hall

John, I cannot help with dimensions, but all I ever did was install the insert..I never indexed it to anything. I do not recall reading anything in the maintenance manual. Regards, Tom
tm peterson

John,

I have attached a photo of two I dug out in the shed. They show the layout of how they came apart and are exactly how they should be. I measured the balls with a caliper and they were both half inch exactly (12.8 mm). As far as I am aware the balls were all the same size, but do check that the ball slides freely inside the guide. The guide does not have to be orientated in any particular way except that the big diameter end goes in first (as in the photo).

Bob Schapel

R L Schapel

That's great info thanks Bob - just as I thought, and appreciate the confirmation. If I take a photo on my ipad, how the #### do I send it to the BBS?? By the way, a washer had been added to the outer end of the spring, presumably to increase pressure on the steel ball. But that was in the cap which I have rejected, where the sealing surface was corroded.
J.P. Hall

The Moss Motors catalog has a useful INFo sheet on rebuilding the oil pump, and goes into enough detail to get it right.

A worn or corroded covers can easily be surface-ground, but be sure to check the gear length then.

Tom Lange
MGT Repair
t lange

Roger that, Tom - I'll go to that tonight, while keeping one eye on the tennis.The mating surface of one of my spare covers is good and clean; the only tricky bit (very minor) was that the PO had a cut-down washer instead of a circlip retaining the driven gear, and that the o/d of the circlip is governed by the diameter of the recess in the cover. Lucky the box of odds-n-sods came up trumps.Thanks for the input. John.
J.P. Hall

Found the info sheet - very useful,and looks like I should undo everything while it's still a rolling chassis, and double check!I hadn't taken off the driven gear so I think I will, plus check end float with more accuracy.John.
J.P. Hall

Hello John. Be careful when you press off the gear. once you remove the retaining clip deburr the groove. Press the shaft down only about 3/16 inch, lift the gear up and put a soft metal piece under each side of the gear then press it down another 3/16, repeat until the gear comes off. Otherwise you press the woodruff key into the bearing. The soft metal (brass or aluminum) prevents damage to the gear.

Butch
R Taras

This thread was discussed between 02/09/2014 and 04/09/2014

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now