Cadillac Tech Tips - How to fix it Discussion, rusty bolts removal tips in Item Specific Cadillac Discussion; anyone have any good tips on how to get rusty bolts loose and out without breaking them? i am using ...
anyone have any good tips on how to get rusty bolts loose and out without breaking them? i am using p.b. blaster, but am hoping maybe some of you have something that can help me. give me anything, thank you.
p.b. blaster worked for me after spraying them for 2 weeks. However, you will find that some of them will never get loose no matter what you do (or at least I did). I ended up with 4 that I just couldn't get after 3 weeks of spraying, and eventually torching. Anyways I ended up just snapping them on purpose, taking the manifold off, and then taking the heads to the machine shop to get bored and rethreaded.
If you don't feel like spending any money, i have been told that you can take a cutting torch to them and the steel will melt and the cast iron won't. Not too sure on that one though.
I've found that not all rusted fateners can be treated to remove. When the two metal surfaces get corroded together in such a way heat is the only way to get them to release a bit in order for the penetrant to work it's way into interfering with the bond. Depending on how much time you have, access to the fastener, and so on, I'll heat two surfaces as equally as possible several times. Expansion/contraction IS MOVEMENT, that's what frees up corrosive welds. Just as the metal is cool enough to apply the penetrant I'll soak it, and then repeat as much as 4 or 5 times. I'll then test it first tightening it just to stress the surface tension and the loosen to see if it breaks free. This usually works.
Then there is the drilling method. Starting with the smallest bit I can and working up to as close to the minor diameter of the bolt/stud as I can. It weakens the structural part of the fastener. That's depending on all other factors too, location, time, tools and place, and so on.
And as some have mentioned, theres always the acceteline wrench, but if possible I'll grind the head off smooth, remove the unit being held in place, and then work on the remaining fastener to loosen it hopefully saving the internal threads. If it's a through bolt and access to both ends, blow that sucker off and punch it through.
If all else fails, Heli-Coils are cheap!
Get yourself a MAPP gas torch for $40 at Lowes...those burn hotter than propane which means you don't have to wait so long when heating things up. Just be careful/aware of what is around whatever bolt you're heating.
Heat the bolt with an acetylene torch until it's red hot. It expands but the bolt is restrained by the metal it is screwed into and collapses on itself. When the bolt cools it contracts and loosens. If you twist the head off anyway the answer is a TIG welder. If the bolt is broken off flush with the surface, build it up with the welder until you can weld a nut to it. When it cools put a wrench on it. If you twist it off again, weld a nut on it again. A rusty twisted off bolt is sometimes loosened by smacking it with a very sturdy punch and hammer to drive it down and make something happen inside. Twisted off manifold bolts can sometimes be removed by building up a lump of brass on the bloody stub and grabbing it with vice grips to twist it out. Which of these techniques you use as well as many others depends on the circumstances. I've been cleaning up other peoples messes for 50 years and have a pretty good reputation in the area. The absolute last resort is drilling and "easyouts". 90% of what can happen is bad.
3 tricks I use pretty much every week if not day. I (if area alllows) heat up the part that the bolt is going into NEVER HEAT A BOLT UNLESS ITS LAST RESORT, it will soften the bolt and guarantee it will twist off.
OK cheap trick in a pinch a 6 dollar propane torch, a parrafin stick(candle, gulf was cut up)get it hot and wipe some wax on it and let it wick into the threads and keep heating and wiping for a time then give it a shot.
Another trick I use all the time is to heat the part with the hole in it to cherry read then strt placing synthetic oil on the threded area as it cools it will pull it in and the synthetic oil willlet it work at a hotter temp and still leave it hot to try and move it (and rust is soft metal that will become "ball bearings" on a microscopic level and help it release) and heat and oil and move it and keep it up and usually it works free but you do need good wrenches for this (the 7.99 set from big lots aint gonna cut it).
A third which I dont like but one of the techs at work will use his air hammer to deform the nut on innter tie rods to free them.My problem is that if the hole in the nut has an internal dent it leaves 2 valleys on each side and lets them lock up even worse and if the person doing it is stupid it can destroy AND lock the nut nearlt permanently.