mannyo1221

The coolant expansion tank in my D3 has a crack right where the return pipe enters the tank so it was leaking.

Anyway got a nice new replacement ready to go on, except I am stuck at the first hurdle and what should be a 10 minute job is turning into a nightmare.

I've disconnected both the top pipes, and went to undo the three bolts, and discovered that all three bolts are just spinning on the captive nuts. They are loose but no amount of undoing is exposing more thread.

Has anyone done this job before and had this happen to work a way around the problem. I've already tried a mole grip on the lower single bolt, but cannot seem to get the bolt to undo, so I am guessing corrosion is the issue.

mannyo1221

I've attached a picture showing the break in the tank, I don't think although not sure if I can patch that at all.

the_duke

you might have to cut/drill the bolts to remove them and then figure out how to re-attach the new tank. People have epoxied brass fittings into tanks to get by until a proper fix could be made but as you are already so close I'd install the new tank.

Mike141

One of my bolts were just spinning too when I replaced my tank. I tried to grab the nut through the fender but it must've been stripped so I ended up cutting it off with a hacksaw. I replaced it with a nut/bolt of similar size. All 3 of yours are messed up? That stinks. Hopefully you can create enough room to saw them off.

the_duke

Or just drill the heads off. You might have to hold the bolt head with a pair of needle nose vise grips.

doddski

I did this job on my 4.2 last year - mine cracked in the same place
My biggest hurdle was dropping the spanner, and having to pull all the splash trays from the under side to get at them...

Not a big job, but i didn't have issue with bolts.

There was a hose on the underside of the tank too which you had to pull the tank up, to be able to undo the clamp.

mannyo1221

Thanks all for the replies so far, the time difference between myself and you all mean a long delay.

Yes its all three nuts spinning.

I've worked out this evening you can get access to the other side of the top nuts from the wheel arch, and I've spent ages today using grips on the other side and a wrench on the other trying to get the bolts out, but no matter how good a grip I get on the nut the grips just cannot hold the captive part.

It's been suggest I try using a soldering iron to melt away the plastic around the bolts so I can at least get the tank out and replace it, an then somehow attach it to the car temporarily using tie wraps. The problem is the plastic seems pretty thick and obviously designed to withstand heat.

the_duke

I still stand by my suggestion to drill the bolt heads off. That will be the easiest way.

mannyo1221

Quick update,

I've now cut the old tank out and have a picture the same as dodski except that the three bolts and plastic remains are in place.

Today, weather permitting I am going to remove whats left of the plastic and cut the heads off all three bolts as they are now dead easy to get at.

Before doing anything though, first thing I'll do is put some tape across that lower coolant pipe to stop any rubbish, including bolt heads dropping in there as that would be the last thing I need.

mannyo1221

And another since its the middle of the day here.

I've now got the new tank in, although its not permanently attached to the car.

I used a soldering iron to melt the remaining parts away from the bolts and once all the plastic was gone used a Dremel to cur through the bolts and take the heads off. I am still left with the remains, but they are partly supporting the new tank.

The car is now running again, and will look at a more permanent fix in the future.