MD pre cups. Need suggestions.

lbg57 · Apr 18, 2010

Anybody have suggestions on how to remove the pre combustion cups out of an MD head without taking the head off? I just got the injectors rebuilt and am starting to reassemble. The previous owner had the wrong pre cups for these injectors in the head. I have the correct ones now but can't get 2 of the old ones to move.I don't want to take the head off till later this summer but need to get it going now. Any help would be appreciated. Thanks.

Andrew Z · Apr 18, 2010

this is not much help, but there is a special puller
for them. I dont think you have to pull the head
either to remove.

Andrew

pete 23 · Apr 18, 2010

They are fun indeed. Do you have the gasket out. Sometimes it alone can make that cup very hard to get loose. A brass drift tapping down inside of it may help. Of course you would want to plug the hole so no derbris can fall inside. I never had a factory recommended puller either and they can be frustrating to get out. When they are installed with new gaskets and clean bore they are so easy. Normally I used a snap ring pliars and just reach in there and pull them out. Tried making a puller once but it didn't work out. Requires a real close tolerence to expand and grip properly.

Owen Aaland · Apr 18, 2010

Pete, you haven't missed much by not having the the puller set. If they are not stuck too tight the puller can remove them. If they are really tight the puller adapter just slips off.

pete 23 · Apr 19, 2010

Owen, I often wondered if they actually worked as there isn't anything to grip to and no taper.

Owen Aaland · Apr 19, 2010

The outside of the puller adapter has some serations machined into it but the precups are so hard that it doesn't do much but polish them on the inside as it slips off.

MD pre cups. Need suggestions.

lbg57

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Andrew Z

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pete 23

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Owen Aaland

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pete 23

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Owen Aaland

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