Pacbrake pyro plug removal (or not)

[PVasilauskis]

Looking for suggestions on removing the plug out of the aft thermocouple hole in the Pacbrake elbow.

We're taking the RV out next week so I don't want to try anything that could leave me royally screwed. I just installed the gauges Wed. if it wasn't for this plug that would have been less than a one day job. I tried soaking it with Liquid Wrench overnight, got a socket set of allen wrenches and a breaker bar to really crank on it, nothing. Applied some heat with a propane torch but I didn't want to go nuts with the heat and crack the elbow. I know it's an exhaust fitting but how would it take to being heated with a torch? At one point I thought of hitting the plug with a blast from an upside down can of canned air to shrink and thermally shock it. (you know, the spray can you use to blow the crumbs out of your keyboard with. Turn it upside down and the fast evaporating spray makes a good spot cooler of components) Any thoughts?

 

[seafish]

A product called Aero Kroil in an orange can is an EXCELLENT penetrating oil that blows Liquid Wrnech and WD40 out of the water. I have used it in many times successfully in difficult removal situations in the past. Also, although I have never tried it, some engineers here claim that 1 part ATF mixed with 1 part acetone is even substantially better then Kroil in terms of penetration and loosening fittings.
It is also useful to try getting a little movement in the fitting by first tightening it, then loosening it. I don't mean actually turning it lots tighter, but only trying to see if you can get it to move clockwise a fraction of a turn before going counterclockwise. Do this only after you use excellent penetrating oils. If it was a nut (not an allen wrench) you could put an impact wrench on it on tighten and then give it a few taps, then loosen... the impact taps and tightening actually help break the physical bonds of the frozen joint. If the allen wrench size is large enough and you have a socket type allen wrench that fits your impact wrench, you might try this, but I would NOT do it with a small (1/4" or less) allen wrench for fear of stripping out the inside of the fitting. I would also only do this if you can get a nice, straight on access to the fitting with the wrench, agian for fear of stripping the inside of the allen head. Good Luck... I am sure other people will chime in with even better ideas.



Also, please edit your signature in the your TDR "user control panel" in order to include your basic truck info so that all members know what truck you are driving.

 

[CKelley1]

it is best to place the probe in the exhaust manifold. if you keep it in the pac just remember there is a nonlinear drop in egt across the turbo your egt readings will be roughley 350* lower. it works just as well and that is how all the big trucks are. as far as the plug if you are bent on installing it there, heat the housing up around the plug to a orange glow and unscrew the plug. about half the time the plug will twist into. next let it cool down slowly and drill out the plug. start with a small bit and center it the best you can get it take it up to the size required for a tap and retap. most of the time you can actually peel out the plug threads amd start the tap in the existing. this time put antisieze on the egt threads

 

[Wingate]

I have had tons of success at removing pipe thread plugs by taking a hammer and "warming up" the offending plug. Use a 2-3 lb hammer and give it several sharp raps right on the head of the plug. 99 times out of 100, it will unscrew after that.....

Kano Kroil is a great penetrant, also ZEP 45...

 

[PVasilauskis]

Well I have looked for Kroil all over the place, nobody carries it around here. Ordered it online which means I won't have it until we get back. Just finished up my shift this morning. I gotta change the oil and filters tomorrow before we leave this weekend, I'll heat it up again and try beating on it some more. If that don't work, when we get back I just may end up pulling the Pacbrake out and working it one the bench.



On a side note, I have looked at drilling upstream the turbo into the side of the downcomer where many say it's "supposed" to go and I'm wonderin' how the heck do you get a drill straight on in that area? There's an A/C line that looks like it's right in the way. While I haven't tried to see if it will fit but I'm sure my drill with bit is longer than the space between that line and the manifold.

 

[Pacbrake]

Hello, this is Chris from Pacbrake technical services. We reccomend putting the pyro into the exhaust manifold to ensure accurate readings. But if you want to place it in the elbow there are two plugs, make sure you have the correct one. The other is used for checking back pressure. Here is some info on identifing the correct plug. corrhttp://www.pacbrake.com/PDF/L5675. PDFect plug.

 

[PVasilauskis]

Yep, got the right plug.



Finally got that puppy out. Copious amounts of heat with a propane torch and a last ditch effort with some PB Blaster. Wasn't sure propane was going to get it hot enough but that's all I had to work with. Unfortunately the hole is 1/4" NPT and the fitting that came with the thermocouple is 1/8" NPTF #@$%!

 

[Wingate]

Thats an easy fix... . buy a 1/4" to 1/8" bushing reducer.

 

[PVasilauskis]

Did that, the problem with that is it's brass. I know one of these posts I saw a brass fitting screwed right into the top of the manifold. Even though that's a higher temp & high pressure than mine will ever see and it appears to be doing fine, it still doesn't give me a warm fuzzy. I have a 1/4" steel compression fitting on the way that I'll swap out when we get back. Right now the pyro hasn't come off the low peg so I need to go out with the fluke and poke around and figure out what's wrong.



This is apparently all my fault for deciding to throw on a set of gauges two weeks before we take the RV out. Nothing is going to go easily with this install.