Trouble removing oil pressure relief valve. 48 DeSoto

[MarcDeSoto]

I know from past experience that the oil pressure relief valve must be free to move in the its cylinder to relieve excess oil pressure in the block.  So I checked it and its stuck tight.  I think the last one I removed had to be destroyed to come out.  I think I had to drill it out.  I put this one in its hole with oil, but that was 40 years ago!  It's stuck now, so I hammered a plug remover with reverse threads to try to break it out.  After soaking it in WD40, I hammered the 3/8 remover in and put a 5/8 socket on it with a breaker bar.  It would not budge.  So I will try using a flame to see if that helps.  Anyone have any other ideas on how to get it out?  

 

 

[Bryan]

Be careful and don't damage the inside surfaces. Heat around the valve on the outside and not in the hole.  Maybe get a can of electronics duster (compressed air). It gets super cold if you shake it.  That's why the instructions say don't shake. Heat the surrounding metal up and spray that into the hole to cool the valve body.   Only other thing I found is use an impact wrench on LOW first.  Use it on low a few times first, maybe heat the body up and try a little higher setting.  That really helped with my crank nut when brute force would not.

[Sam Buchanan]

Instead of WD-40 try a mixture of acetone and automatic transmission fluid.

[harmony]

4 hours ago, Sam Buchanan said:

Instead of WD-40 try a mixture of acetone and automatic transmission fluid.

I've heard of this concoction several times before. What are the proportions? 

 

[kencombs]

Yes to anything but WD40.  first it is not a  penetrating oil.  Second, when it evaporates it leaves a residue at least guns coated with it get sticky over time.  Good at removing stickers and glue though.  Straight ATF is better, add acetone makes it even better.  About half and half, shake well before using as it separates. 

 

Or if you feel the need for ready-made concoctions, There are many penetrants on the market. PBBlaster, Liquid Wrench, Kroil etc. 

[allbizz49]

PB blaster and heat. Marvel Mystery oil with a bit of acetone is a good one too. 

[Sniper]

When the valves on my core 230 were stuck I had several that would NOT unstick.  I pretty much tried all the concoctions and suggestions mentioned above.  None worked on the recalcitrant ones.  Then I talked to some old timers and they said "use brake fluid".  Not to be confused with "break fluid".

 

It worked great.  Been almost a year now and they are still unstuck, turned it over this morning, by hand.

 

I would try brake fluid.

 

 

[MarcDeSoto]

thanks for all of these great tips.  I'll some of them and report back.  Brake fluid sounds pretty good!  Marc.

[MarcDeSoto]

A friend of mine said that maybe my extractor tool is pressing the relief valve out and making it even more tight.  That sounded right.  So maybe I will have to drill it out.  I could drill a hole and then thread it for a long bolt.  Then pry the bolt out.  

[Sam Buchanan]

7 hours ago, harmony said:

I've heard of this concoction several times before. What are the proportions? 

 

50% acetone and 50% ATF should do the trick.

[Bryan]

2 hours ago, MarcDeSoto said:

A friend of mine said that maybe my extractor tool is pressing the relief valve out and making it even more tight.  That sounded right.  So maybe I will have to drill it out.  I could drill a hole and then thread it for a long bolt.  Then pry the bolt out.  

Maybe use something like a slide hammer on the bolt for pulling axle races & bearings.

[MarcDeSoto]

Does anyone know is new plungers are available for a 48 Desoto with a 236 engine?

[Sniper]

Patience, soak it, lightly tap it, use air pressure to pop it out, if you can seal up the passageways.  Last thing you want to do is mess up the bore trying to get it out.

[MarcDeSoto]

Ok, made some progress today.  I broke the plunger loose with the extractor tool plus heat.  but now I have a new problem.  Even the the plunger turns easily now with a socket, but I can't pull the extractor and plunger out of the hole.  The pliers keep slipping off of the 1/4" part of the extractor that sticks out.  We tried drilling a hole in the tool, but it is too hard to drill into.  I tried using vise grips, but they slip off too.  Does anyone know if I can get behind the plunger if I take the oil pan off?  Any more ideas?  picture shows extractor tool in the hole.  

 

Marc.

Edited April 5, 2022 by MarcDeSoto

[kencombs]

I looks to me as if one could get a little pry tool  under the head of the extractor.   I have tack pullers, tiny pry bars etc, but would probably sacrifice an old screwdriver. Heat, bend, grind etc.  The leverage would be much better than a straight pull, IF there is as much room as it looks from that angle.

[MarcDeSoto]

I finally removed the extractor took with pliers.  It doesnt look like I broke the plunger loose.  Now the problem of removing the plunger.  Well the plunger is much softer steel than the tool and it has a hole in it already.  I can't get a hand drill in there unless it's at an angle.  They do sell right angle drill adapters.  But I'm thinking I could go into that hole with an easy out.  The problem with an easy out is it doesn't give you a nut or lip on the end to yank it out.  

[MarcDeSoto]

Just ordered three more tools that might work on this.  A 90 degree drill adaptor, some easy outs, and another extractor tool set.  Maybe they will do the trick.  

[greg g]

Some folks have screwed long sheet rock screw into the hole, then used body work slide hammer to extract the plunger.

[Young Ed]

I believe the great Don C pulled his using a tap that he threaded into the plunger and then pulled both out. 

[Dodgeb4ya]

7/16" X 14 tpi flathead head bolts are what I have used at times to pull those  plunger valves out. 

[40phil41]

I got mine out by firmly attaching vice grips at 90 degrees to the plunger and hamering the vice grip from down below. Came right out.

[MarcDeSoto]

Finally victory!  I ordered two kinds of easy outs from Amazon.  The ones with the threads didn't work because it didn't have the right size.  but the ones with the tapered edges worked great.  I think I can still use the plunger even though I put a small hole in the side when I tried to drill it at an angle, which I smoothed up with sandpaper.  

 

 

[Bryan]

Great news. Glad you got it out.  They aren't expensive, would measure diameter and get a new one.

[MarcDeSoto]

$60 plus shipping for a new one on eBay.  I'm suspicious of the one on Ebay because because it is a one size fits all.  When I look in the Dodge and Plymouth Parts books they have a different part number for the plunger than the DeSoto Parts book.  Also the Plymouth and Dodge plungers are short and squat, while the DeSoto and I assume Chrysler plungers are long.  The plunger on Ebay sold by MoparPro looks like it's the one for Plymouth and Dodge.  So they must have a different smaller size for the Plymouth and Dodge engines.  So I think I'll keep my original plunger.

Edited April 7, 2022 by MarcDeSoto

[Bryan]

Go to Vintage Power Wagons. That's where I got mine. Should be 1/2" or 5/8".  Measure yours. Just get the plunger.  Best to call them up and check shipping before ordering. Calling works faster than their form.

Edited April 7, 2022 by Bryan