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How to remove fuel servo studs?

AK-Models

Member
Need to remove 4 studs from the sump and they turn out to be very stubborn.
I have tried using 2 nuts and even 3 nuts but no luck, tried to drill a hole thru to pin one of the nuts but it only ripped the stud. I am little scared and puzzled on what to do next. I have not tried to use heat, concerned it will leave discoloration or something...

Any ideas or special techniques out there?

P8030017.jpg
 
BreakFree

Those studs look to hold the fuel servo. So, that area is not a good idea for heat as residual fumes could make a dogs-breakfast out of it.

Try some breakfree (or similar product), let sit for a period of time, and give it another whirl.
 
Find a friend with a Snap-On stud puller. Not cheap, but they cost WAY less than a sump. Or...become the guy in your circle of friends who OWNS the Snap-On puller and you'll make even more friends..... ;)
 
Find a friend with a Snap-On stud puller. Not cheap, but they cost WAY less than a sump. Or...become the guy in your circle of friends who OWNS the Snap-On puller and you'll make even more friends..... ;)

+1 - and Heat from a heat gun would not hurt at all, no open flames! That is basically a zero clearance fit and with heat, the sump (Al) will expand more than the steel (Fe). The Snap-ON tool will give much more thread engagement to avoid issues from the double nut method.

I've never had much luck with penetrants in this situation.
 
Heat gun is fine, also when you do get it to move, don't force it to unscrew all at once----if it is still fighting you, rock back and forth and use some penetrating oil as needed------I like Kroil http://www.kanolabs.com/google/

I use a star washer between the two nuts when removing a stud------jam the nuts together really good, then turn the top one to remove the stud.

Good luck, it can be done.
 
Stud removal

Heat the sump up to at least max allowable oil temp with a heat gun. Like Mike said use the top nut as the primary place to apply unscrewing pressure. You may need to use a 2nd wrench on bottom nut to apply a small amount of tightening force to keep the nuts clamped together while unscrewing with the top. If still no luck you can tap on studs in vertical direction with a hammer (brass is good) and then try spraying the stud with something cold like contact cleaner.

Don B

RV 9 Rebuild in Progress
 
+1 - and Heat from a heat gun would not hurt at all, no open flames! That is basically a zero clearance fit and with heat, the sump (Al) will expand more than the steel (Fe). The Snap-ON tool will give much more thread engagement to avoid issues from the double nut method.

I've never had much luck with penetrants in this situation.

FYI, I am pretty sure the sump is Magnesium for the Lyc 320's and 360's not AL, but the principle is the same. Just more important no open flames for heating.
 
Snap-On stud puller

Find a friend with a Snap-On stud puller. Not cheap, but they cost WAY less than a sump. Or...become the guy in your circle of friends who OWNS the Snap-On puller and you'll make even more friends..... ;)

Snap-On stud puller is coming this way... I will be the guy with "friends" :)
Looking at the youtube video, looks like it should work like a charm.

Thanks guys.
 
Sumps

Most of the more common 320 and 360 sumps are aluminum. A few odd balls are magnesium. I believe some of the Piper Arrows are magnesium sump. Lycoming IO 360 with aft mount injector???
 
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