Morris Minor Owners Club

I've fitted a remote reservoir using 3/16 Kunifer plumbed via a banjo tapped into the rear of the master cylinder reservoir. Replaced the m/c reservoir top cap with a non vented version, sealed with the original fibre washer. I can't get this to stop seeping fluid by tightening the cap, even though it is under quite low fluid pressure. Do I need to find a suitable size copper washer, or would Loctite or similar on the threads do the job once I've drained it?

Mark

A suitable thread sealant would do the job ... but the gasket is there as the seal, not the threads...

Copper washer is ideal. If using thread sealer, ensure that it does not contaminate the fluid.

The size of the washer is :
1 1/4" x 1 3/8"
29 x 36mm

Regards
Declan

Thanks Declan and others. Nearest standard washer I'm finding so far is 36x30x2mm - do you think the 1/2 mm additional clearance will make a difference?

Mark,
It depends on the OD of the thread used on the non vented blanking plug.
The ones I use have an actual thread OD 28.40mm. The 30mm should be OK.
Regards
Declan

Someone suggested PTFE plumbers tape to me and that did the job of sealing the threads when I fitted a similar reservoir kit.

If using PTFE tape then treat it like sealant and be really careful to avoid contaminating the fluid - the threads on some caps will protrude below the thread in the top of the cylinder, and this could lead to fragments of tape dropping into the fluid and then working into places where you do not want them. A copper washer is by far the best solution.

I will re-iterate - the threads are not there to seal against fluids. PTFE tape is also inappropriate - it is used for tapered, not parallel, threads as a sealant. Washers are required for parallel threads - that is why flat mating surfaces are provided! PTFE tape on parallel threads is a bodge.

Copper washers have arrived in the post today, and I will drain down and fit once I've finished installing the engine and box!

Thanks for all the help

Mark

May need annealing before fitting? I always do it with copper washers to avoid any risk, unless they are the compressible types, such as on spark plugs or some sump plugs.

RAB

Copper washer annealed and fitted - job's a good'un. Thanks all!

Mark

Well done. Copper work hardens, so I have always annealed bits, just in case.

I had a second hand Honda 50 motorbike (not the scooterette) in about 1965/6. I did a lot of miles before I completely trashed the engine by the summer of ‘67. The head was off about half a dozen times, likely more, but I used the same solid copper head gasket, after annealing, every time the engine was rebuilt with no problem.

RAB

Just received mine in the post,not a happy bunny,they are measuring 30.5 x 35.8 ( advertised as 30 x 36 ) , and they look a little "weedy" , can anyone point me in the right direction for 29 x 38 ( size of original fibre washer ) , or failing that fibre washers of that size ?

Many thanks

John

oliver90owner wrote: ↑Sat May 12, 2018 10:02 am I will re-iterate - the threads are not there to seal against fluids. PTFE tape is also inappropriate - it is used for tapered, not parallel, threads as a sealant. Washers are required for parallel threads - that is why flat mating surfaces are provided! PTFE tape on parallel threads is a bodge.

Thanks for that, copper washer now ordered. I think the problem was that a casting mark in the MC projected so that the cap wouldn't go right down and seal the fibre washer. Will get it drained down and fixed.

I spoke too soon! Still very slight weep from copper washer, which is a loose 30.5 - 31 mm ID as described by Sleeper. This despite serious tightening of the cap with a long ring spanner, and a bit of hammer persuasion on the end. I'll repeat John's plea for a better supplier of 29mm ID copper washers.

Correct ? washers ordered from ESM.....will update.

John

A parcel arrived this morning...only ordered Sunday 17:00 ish...washers from ESM..not perfect but will do for now
ID.30mm OD.38mm
Would post a picture but.

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Whatever that means....

John

I've got hold of a crushable copper washer intended for a motorcycle exhaust. ID 29mm, OD 37mm. Might be a few days before I can fit, but I'll let you know how I get on.

Try a smear (just a smear!) of Automotive (not bathroom!) RTV gasket sealant on each side of the washer. Make sure all is clean and dry, fit the plug, leave for 24hrs.

Regards

Ian