1996 XJ 353,000 miles.

What is a good gasket removing potion for factory gaskets?

When I replaced my thermostat and radiator, by far the longest operation was scraping off the gasket from both the block and the housing with a razor. Chrysler even glued in the thermostat and I got to scrape out that area for a while. Finally got it all flat, the only material left was filling in low spots as far as I could tell. Brake cleaner just bounced off, had no effect at all. When I installed the new one I used some Permatex brush on High Tack at the top of the thermostat to keep it from dislodging, it still did once, and installed the Fel Pro gasket dry. Still no leaks weeks later.

Sometime in the near future I'll be doing the differentials and those are stuck on from the factory too. Is there anything like acetone, mineral spirits, or something to use to get that gasket and glue off? Will be using a Fel Pro gasket there too.

 

Scraper and wire wheel.

 

Yeah, gasket removal is a real PITA.

If you can use it on the particular mating surface, a good wire brush on a drill is pretty effective.

There are some gasket removal sprays and the such that they sell at the local parts retailer or hardware store. A good gasket scraper (the screwdriver one) is helpful too.

Then the best thing you can do to help yourself in the future is to use a quality non-RTV gasket whenever possible. They make some good ones for the differential.

 

I use a scraper for removing inspection stickers off glass, along with some brake or parts cleaner, letting it soak a bit if the gasket is hardened. Sometimes soaking helps, sometimes it doesnt. If it needs it, ill fire up the compressor and use a scotchbrite pad. If you get old gasket material in the threads, clean them out. Or put the fasteners back in a couple threads and clean around them to keep dirt out.

 

These work pretty good and dont eat away at the metal.

 

A razor blade with something like this.


Then clean it up with a blue cookie, the one out of the Harbor Freight kit, on my die grinder very gently.

https://www.harborfreight.com/comple...kit-43029.html

 

What's the name of this thing, and what tool do you use it with?

 

3M Roloc Disc.
Roloc disc holder with a die grinder.
Guess you could use it with a drill.

 

Ralph is correct.

I normally use it on the drill. You dont have to spin them at a crazy rpm to work good. The green one is the best all around compound IMO.

 

A razor blade and Gumout carb cleaner works great and should be all you need in most cases. For applications with critical clearances, bearings, sealing surfaces and related I recommend against use of a wire wheel or brush, 3M Roloc bristle disc, Scotchbright pads, sandpaper or other abrasives. In using these some abrasive particles will be shed. You risk contaminating components with the hard and sharp particles. For the less experienced you risk scratching and gouging the sealing surfaces or taking off too much material in one spot, making sealing difficult. Both Ford and GM have issued technical service bulletins addressing problems of abrasive disc use on engines. In some cases engine failure was traced to techs using abrasive materials to remove gaskets. An example can be found in GM TSB 00-06-01-012F. https://static.nhtsa.gov/odi/tsbs/20...82814-5448.pdf

 

Not convinced regarding my post above? Here is more reading on the use of abrasive discs in engine work. As the author in the article refers to it – “Rat Poison” for engines. https://www.underhoodservice.com/sur...engine-repair/

Another area to avoid is use of glass bead or abrasive blasting of engine components. I am aware of a case where an expensive and time consuming rebuild of a VW air cooled engine was destroyed in the first few seconds of operation due to abrasive residue imbedded in valve train components. Yes, bead blasting of engine components can be done but that should be followed by meticulous ultrasonic cleaning.

 

Even though this is for removing the diff gaskets, I still wanted to stay away from the abrasives. That is why I was asking for a chemical solution, and because I tried brake cleaner on the factory thermostat housing gasket and it just bounced off.

Does carb cleaner work better than acetone, mineral sporits or lacquer thinner?

 

Gumout Carb/Choke and Parts Cleaner is mostly acetone with some toluene. There are several formulations of brake cleaner today so some may be more effective for gasket removal. I believe I even found a "safer" brake cleaner once that included water. I have not done a side by side comparison so I will not guess if one is better than another. Gumout is easy to find, low cost and easy to use. For RTV gaskets there are removers intended especially for that application.

Even for cleaning a differential housing you don’t want to risk pieces of hard metal wires or abrasives wearing the gear mesh surfaces or bearings.

 

This is what I got for when I do my valve cover gasket. You'll also need this

 

Not going to use anything like that around gears or around an opening to the engine. It does seem fine for removing crud from the covers while they are away from the engine and can be completely cleaned before reinstallation. But not around the diff itself, etc.