Sheared Bolt in Coolant Pipe

[Andy47]

Hello All,

This is my first post, but I have been a member since I purchased my MK1b. I make the most of the search function on the site to find solutions to any issues I have previously had, and I never needed to ask anything new (nor felt I was experienced enough with Mk1’s to give advice to others). I’m in a slightly different situation now, but a familiar one I am sure...

Last night I started to drain the coolant out of the car. Followed the usual steps, I moved onto the radiator pipes running underneath the car. Whilst taking the drain plug out on the rear most one, what I initially thought was the bolt undoing felt more and more like a bolt necking. Despite my best efforts, I sheared the bolt.

The shear is close to the head, so there’s a good proportion of the threaded section of the bolt inside the coolant pipe wall and there is no coolant leaking out. So this leads me on to my question – What do you think I should do? I have considered the usual methods such as drill and re-tap, although I had concerns with doing this to a coolant pipe. Even considered doing nothing and hope that it wouldn’t leak when hot.

As indicated above, I couldn’t find anything on the search function with this problem on this specific area, so before I go ahead and do anything I would be grateful if I could hear the suggestions from the more experienced members of the forum!

[dopiaza]

Hi,

Many people don't bother undoing those when doing a coolant change, just do a good flush with plenty of clean water until the water runs clear. It's unlikely there will be a leak as the thread will probably not have shifted at all so the seal should be as good as it was before.

You could use bolt extractors to remove the plug, but no guarantee of success there although you can pick them up cheap on ebay so could be worth trying.

http://cgi.ebay.co.uk/5-TAP-DAMAGED-BRO ... 286.c0.m14

Last resort would be to replace the pipe - you really want to avoid that if at all possible.

HTH
Graham

[ligertigon]

Perhaps its not the threads that seal but the bolt head? Did it have a gasket on it? as the epc looks like there is one!

http://www.toyodiy.com/parts/p_E_1988_T ... 603.2.html

Personally, I would never touch these but many buy the red haynes and follow it to the word.

I would continue with the coolant change and run car to hot and check for leaks, but if it does leak while driving, it could be a hefty bill, with that in mind I would go to a garage with a mig and ask them to tack it with weld.

[cartledge_uk]

I have always left that one too.

That is a terrible bolt to go, the easiest solution would be to weld the hole in the pipe up.

anything else may casue excessive time and or money due to the awkwardness of getting there.

[Andy47]

Thanks very much for your input, guys. Didn’t realise some people didn’t bother removing these bolts. Thanks for the link to that item Graham, and thanks ligertigon for that link too – I think mine had a metal washer rusted tight to the bolt head (not sure whether it corresponds to that part number though).

I filled it back up with coolant earlier and ran it until it warmed up. It’s not leaking atm, but I’ll go for a careful drive at the weekend to see whether it keeps its seal. However, I think I will get it welded as suggested - I definitely don’t want to risk damaging the engine.

Thanks again to all!

[System-G]

As above just leave the bolt thread in place. If it starts leaking, then weld it up

Also make sure you bleed the system properly. Air getting trapped inside can lead to head gasket failure.

http://www.mr2mk1club.com/repairsp13.html

[kevin..in]

as per other replys I wouldn't attempt to undo that drain bolt
moral being before you attempt anything unfamiliar just ask, everyone here without exeption will help and advise with pleasure
this is what the forum exists for and thrives on

quickest solution to the problem if the (now headless) drain bolt leaks would be to cut that section out and fit a short section of rubber coolant hose and a couple of clips
as for welding I doubt your average bird xxxx blobing mechanic has the skills to do this job, is the pipe stainless steel? was the bolt stainless too? there may be your first problem with welding

[Andy47]

Many thanks again for all the advice and suggestions. Just been for a drive this morning and there’s no leak from the pipe/bolt when hot. Didn’t consider the pipe could be stainless, so best check on that...

[kevin..in]

Many thanks again for all the advice and suggestions. Just been for a drive this morning and there’s no leak from the pipe/bolt when hot. Didn’t consider the pipe could be stainless, so best check on that...

probably the inner end of the bolt (the part that was immersed in coolant for 20+ years) had corroded and mushroomed, so that as you tried to undo it, it had wedged hard in the threads. probably now quite an effective seal but I would keep an eye on it 'till you're certain