rcl700 Posted February 3 Report Posted February 3 Is there a trick to getting the thermostat guage bulb out? I was able to back the jam nut off but the bulb does not feel free to pull out. I don't want to break this because I think it one peice with the guage. Quote
Solution Plymouthy Adams Posted February 3 Solution Report Posted February 3 (edited) there is a removable expansion plug over the bulb in the head....allows you to access from there.....you will need a good solvent to break the rust bond. This is delicate to remove intact....go slow.....and yes it is one piece with the gauge as you state....damage renders it useless unless you perform an effective transplant from a modern donor or luck upon a surviving unit or NOS Edited February 3 by Plymouthy Adams Quote
rcl700 Posted February 3 Author Report Posted February 3 So, pb blast let it soak then just keep slowly pulling shaking on it to work it free of the head? Quote
rcl700 Posted February 3 Author Report Posted February 3 Not sure I understand the removable expansion plug. Can you elaborate? Thanks Sir. Quote
Plymouthy Adams Posted February 3 Report Posted February 3 with all due respect have you looked at the head in the vicinity directly above the bung? You likely will need to remove the bracket that your picture shows that is covering the greater portion of the expansion plug Quote
rcl700 Posted February 3 Author Report Posted February 3 (edited) I went and took a look at my donor motor. I now think I see the plug you are mentioning. This plug needs a hole drilled in it then pry it out, allowing access to see the backside of the buld. From there more lubricant and slowly push back/out on the buld from inside the head?? Sorry I'm a novice at this. This is my first clasic car. The help and knowledge this group provides is invaluable. Edited February 3 by rcl700 1 Quote
DonaldSmith Posted February 3 Report Posted February 3 In the words of the late Jack Carson, "I didn't know that." Quote
Doug&Deb Posted February 3 Report Posted February 3 Be careful drilling through the plug. You don’t want to drill into the bulb. 1 Quote
Jerry Roberts Posted February 4 Report Posted February 4 17 minutes ago, Roofus said: Why not unscrew the nut on the block ? The bulb is probably stuck to the gland nut and that could twist the tube and break it . . 1 Quote
kencombs Posted February 4 Report Posted February 4 51 minutes ago, Roofus said: Why not unscrew the nut on the block ? Looks too me that the nut is removed but the bulb is corroded in place. Removing the core plug and soaking with a rust solvent the gently prying through that access is called for. A solvent that will dissolve rust would be great, maybe you could create a dam of some sort with plumber's putty to retain some evaporust around the bulb? Whatever you use, patience and time will be needed. 1 Quote
Dodgeb4ya Posted February 4 Report Posted February 4 Remove plug...carefully wedge the bulb out. Simple. 1 Quote
Mr.P-15 Posted February 4 Report Posted February 4 RCL1700: This is always fun (I'm being sardonic here). As you have figured out, the problem is that if you twist the bulb receptacle fitting off, (without having removed the ((stuck)) bulb first) you will twist the capillary tube and break it. I cannot see what state your project car is in, but if the gauge unit is free to spin (i.e. not anchored to the dashboard) such that the whole unit spins at the same rate as you twist the receptacle off, you will be able to remove it with no problem. Having a friend hold and turn the gauge around as you turn the wrench can make the whole process easier and protect the gauge unit, but it is just as plausible to do it solo. Putting a strong plastic bag over the gauge will also help protect it. Once removed, it will be easy to separate the bulb and receptacle. Hope that can work for you Quote
Los_Control Posted February 4 Report Posted February 4 I suppose someone needs to say it ..... absolutely be as careful as you can removing it. Even though you are as careful as can be, they were somewhat fragile when new, now they are ~75 years old. The one in my truck looks very good and seems to be in working condition ..... sometime in the past it leaked and no longer works. I have a later aftermarket I was using and planning to use as a donor to repair my original .... it started leaking when I went to remove it. I'm just saying you need to be as careful as you can, if you get it out and clean it up and it still works ..... go buy a lottery ticket. 1 Quote
rcl700 Posted February 5 Author Report Posted February 5 Yes.. I will do my best hoping I can remove it intact. I removed the plug and now soaking in pb blast. Quote
rcl700 Posted February 9 Author Report Posted February 9 On 2/3/2024 at 12:00 PM, Plymouthy Adams said: there is a removable expansion plug over the bulb in the head....allows you to access from there.....you will need a good solvent to break the rust bond. This is delicate to remove intact....go slow.....and yes it is one piece with the gauge as you state....damage renders it useless unless you perform an effective transplant from a modern donor or luck upon a surviving unit or NOS Thank you sir for the information needed to get this accomplished. I soaked it for a week then worked it out today. 2 Quote
rcl700 Posted February 10 Author Report Posted February 10 When reinstalling, should grease or anti seize be used on the bulb to prevent getting stuck again? Being that it's in the water jacket I'm not sure if these products would do much good. Quote
Sniper Posted February 10 Report Posted February 10 It looks like it's brass it's not going to corrode to the Head. I don't know that there's anything you could do to make it easier in the future. But think about it how long has it been screwed into the head? Since it left the factory? Quote
48ply1stcar Posted February 18 Report Posted February 18 Did anyone ask if the gauge worked? If it doesn't work, doesn't need to ne replaced anyway. Quote
Plymouthy Adams Posted February 18 Report Posted February 18 that is a good question but one that does not address the question, removal without damage....and as this was the leading concern, I for one assumed the man had a working gauge and wanted to keep it that way.....maybe I am too optimistic at times......lol Quote
rcl700 Posted February 18 Author Report Posted February 18 (edited) I the guage was in working condition prior to needing it removed. I want to pull the engine. I have verified the the needle still moves with a battery powered heat gun after successfully removing the bulb. I do plan to test the accuracy once I get the cable removed from the firewall. I will use a pot of water and a thermometer the see if the guage reflects the digital reading. When reinstall takes place I will know if a should be making a mental adjustment. I plan to test the upper radiator thermostat in the same manner to check it opens and at what temp. That's the plan anyway. Edited February 18 by rcl700 1 Quote
p15-1948 Posted February 19 Report Posted February 19 I think there is some adjustment at the gauge. think I've read that in some of Chrysler's literature. 1 Quote
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