Replacing DS MM frost plug
Thread Starter
3rd Gear
Joined: Apr 2017
Posts: 3
Likes: 0
From: Nanaimo BC
Replacing DS MM frost plug
86 L98, got the leaking frost plug removed just behind the engine mount (pita). After trying a few times to get a new one I gave up for the day. It's pretty difficult to get a straight shot to press it in. Any tips? I remember reading someone might have used a porta power, which I might try. Also those copper dorman expansion plugs, do they go in easier then you can expand them?
Safety Car
Joined: Aug 2013
Posts: 4,430
Likes: 609
From: Minneapolis Mn
I cannot speak to a Corvette but something we did years ago on another brand of car. It took some crawling and bending but it did work eventually.
Took a piece of threaded rod (about 1/2" IIRC) and one of the threaded sleeves used to join 2 sections of rod together. Put a nut down low and welded it to the rod, hooked that end onto the frame somewhere and put the threaded sleeve on the end by the freeze plug with a large washer in the depression of the freeze plug for the sleeve end to push on.
I think we used some type of sealer on the plug, and using some wrenches used the threaded rod like a press to push the freeze plug in. It took some creativity and wasn't fast but did get it in. Biggest issue was trying to get it to start in straight, but once it was going it did go in. Pick up an extra freeze plug or two in case you deform one trying to get it to start straight.
Another tool that might work is an air hammer if you have the room to get it in and have a blunt tool to fit into the air hammer. Should be able to drive in a freeze plug if there's enough room.
Good luck
Took a piece of threaded rod (about 1/2" IIRC) and one of the threaded sleeves used to join 2 sections of rod together. Put a nut down low and welded it to the rod, hooked that end onto the frame somewhere and put the threaded sleeve on the end by the freeze plug with a large washer in the depression of the freeze plug for the sleeve end to push on.
I think we used some type of sealer on the plug, and using some wrenches used the threaded rod like a press to push the freeze plug in. It took some creativity and wasn't fast but did get it in. Biggest issue was trying to get it to start in straight, but once it was going it did go in. Pick up an extra freeze plug or two in case you deform one trying to get it to start straight.
Another tool that might work is an air hammer if you have the room to get it in and have a blunt tool to fit into the air hammer. Should be able to drive in a freeze plug if there's enough room.
Good luck
Last edited by hcbph; May 1, 2017 at 08:33 AM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Replacing core plugs is a PITA most of the time when engine is installed. Sometimes parts stores will rent installation tool set. I will help some. The deal is to get plug started straight. I normally used the deep verses shallow plug. With the expanding type plugs the hole need to be clean and follow the instructions too tight or loose the plug can pop out when engine gets hot.
Thread Starter
3rd Gear
Joined: Apr 2017
Posts: 3
Likes: 0
From: Nanaimo BC
Thanks for the feedback. Yes I am using the aviation gasket sealer, which kept getting fouled up when it would fall down. I'm going to see about making something that bolts to where engine mount goes to use as a press. All for a $1 part, but it's kinda critical. This is also just so I can try and determine afterwards how water might be getting in the oil :S
Last edited by blazin_jason; May 2, 2017 at 02:33 AM.
Thread Starter
3rd Gear
Joined: Apr 2017
Posts: 3
Likes: 0
From: Nanaimo BC
I'm way too stubborn to take the easy route, even though this isn't even my car! I got a replacement installed tonight, pain free and quickly. Used a piece of 1/4" alum plate I stole from work cut roughly to size, drilled 3 holes, used a small piece of alum tubing to press the new plug in while tightening the bolts. Added in a 1/4" spacer afterwards between the plate and tubing and tightened again to get it in flush. Now to borrow a pressure test kit to see if I can find the next issue(s).
Last edited by blazin_jason; May 4, 2017 at 11:40 PM.
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