Drive side seal not air tight

[alanscottj]

I have put an engine together with new seals from BeedSpeed, done a leak down test and the mag side seal is not air tight, air is escaping through the Cush drive. Any advice? Suggestions of a better seal?

[phil23fair]

Did you fit the halite washer as well as the oil seal?

[alanscottj]

Did you fit the halite washer as well as the oil seal?

I did yes

[Chris in Margate]

Sadly you've got to do it again with new oil seal because that one is probably now suspect. Lots of oil, some put grease and rotate crank slowly as pulling in.
Probably the very worst design on the Lambretta engine !

[Agent Buchwald]

It might be worth checking that the Hallite washer is being compressed enough - they come in different thicknesses and the gap varies.

[alanscottj]

It might be worth checking that the Hallite washer is being compressed enough - they come in different thicknesses and the gap varies.

Cheers guys, I'll strip it and start again I have another seal I'll give that a go with a new halite washer.

[bristolmod]

can get quite tight in that area- replaced my D/S seal earlier in the year and had problems with the plate then touching the crank. Halite washer was too thick.

Also make sure the plate isn't warped.

Chris

[alanscottj]

Am I not right in thinking that it is the seal that would be letting air out, not the hallite washer?

[HxPaul]

The halite washer stops air from leaking out and oil from entering into the combustion area from the gearbox between the crankcase and the side of the bearing.

[wack 63]

A lot of Halite washers are crap nowadays and barely compress so I machine the back of the drive plate to make the step deeper. If you fit the drive plate without a seal then measure the gap between the step and bearing with feeler gauges you will then know what the gasket will compress to. Also don't take it for granted the bearing outertrack is air tight in the casing.