Stripped/Seized Bolts on Skid Plate!

[modelstudent101]

So, figured out I needed a new radiator. I went to drop the skid plate - lo and behold, two of the bolts (both driver's side) were seized and I ended up stripping them out with a 12 pt hex socket (I'm an idiot). I hit them with PB blaster and let it sit overnight. I've tried vise-grip, breaker bar, special sockets, broke 2 drill bits trying to drill it out (18v, not compressor); any suggestions? Do I need a specific bit? I'm worried about using an easy-out/extractor considering how badly the bolts seem to be seized - don't want to have to deal with trying to remove that too.

I've spent hours Googling, reading threads about other people with a similar problem, talking to people at AutoZone and called around some of the mechanics today - each person said something different and I'm not sure all of them understood. Any help would be greatly appreciated!

edit: I can't drive the car. The radiator failed and I'm pretty sure there's less than a pint of coolant in the entire car. I don't want to take it to a shop and have them drive it around to maneuver it - haven't quite found a shop I trust in the Los Angeles area that's close enough for me to use in this particular situation.

 

[96pearlrunner]

why dont you do it through the top if you cant remove the skid plate?

 

[angus]

why dont you do it through the top if you cant remove the skid plate?

Exactly - you can do it this way.

I hope you didn't drive too far with no coolant - would hate to see engine damage.

Now as far as the bolts, I have run across this on so many vehicles but specifically on 4runners and tacomas.

FIRST - if the bolts are not broken off like I see often, then you still have a decent chance to get them off with no more drilling/tapping ahead of you

- Use heat - even if you only use a propane torch it'll help (you'll see why shortly) you want to heat up and cool down the bolts at least 3-8 times with penetrating oil in between.

BEWARE - many of these trucks have lots of oil build up and you can cause a fire using a torch.

Then, you want to "shock" the bolts, hit them straight on with a big hammer - HARD - if your bolts are really stripped ( if they are not at this point - strip them now) - then what I do is get an 11mm socket and an extension (try to use a 1/2" drive impact socket) and use your big hammer to pound it on - at this point it really helps if you have an impact gun but it's not 100% needed - what is crucial is that you keep the socket square and pull straight when pulling your breaker bar/ratchet - its best to plan your angle because you will get the most torque on your first pull. If you are lucky it'll come out - if you're not, the bolt will break, either way you can proceed with the rad job and then if you need you can move to the next step. I've successfully used this procedure for over 20 years and it almost never fails, either the bolt will come out or the head will come off.

What I just did on mine was this.

Mine were broken off already so I only needed to get the broken portion out - after a few heating/cooling cycles with PB blaster in between (I actually favor "liquid wrench") you can drill them - use a 1/8" COBALT drill bit and drill slowly but with as much pressure as you can exert on the drill - DO center punch the hole first - if you are drilling properly, you will see a "string" or swirl of metal coming out of the bolt as you drill (this is called the "swarf") Once you drill it through, go up a few sizes until you reach the proper diameter for the 8mmx1.25 tap you will be using.

On my truck there were 3 broken bolts and the front was zip tied and only really held in front by the tabs.

Now the cool part, as I started tapping the holes - TWO of the bolts started screwing in further and almost ended up falling inside the frame - I then reversed the tap and the the bolts came right out - this was surely due to the heating and cooling with the liquid wrench.

The last one, I had to re-tap the hole but it was really no big deal.

 

[modelstudent101]

I can change the radiator out from the top but I'm going from green to red coolant and wanted to properly flush and drain out the radiator/engine block. AFAIK, you need to take the skid plate off to do this - please correct me if I'm wrong, as this is one of the first times I'm working on my Runner.

Any suggestions on cleaning the oil? I definitely have some thick buildup on the rear bolt... I'm guessing some sort of degreaser and a hose? Or is this more of a bring an extinguisher type of deal?

Thanks guys, mucho appreciado! Saving lives one post at a time.

 

[Unner]

Lots of degreaser and a brush should take care of most of it. It is usually good practice to have an extinguisher somewhere handy in the house though, just in case.

 

[Chris_Harby]

I had the same problem with mine when I put a transmission Cooler on mine. Easiest way I could do it was drill out the stripped bolts and replace them with a different bolt and nut, also use antiseize on the bolts when they go back in to prevent it from happening again. for oil build up in the plate I took a paint scraper and scraped off what I could, then used a scrub brush and industrial grade degreaser to clean the rest.

 

[animator]

I could feel mine starting to strip using a 12 point... so I used a 6 point 12mm socket. No problems.

 

[modelstudent101]

Yeah well I got a 6-pt socket afterwards... too little too late. I'm gonna pick up a torch and some 11mm 6-pt sockets to try and get those bad boys out without drilling. I'll keep you guys posted for posterity.

 

[Cadaverous]

I bet you can get it with some heat. Heat from a torch does wonders.