Thermostat housing bolts

[dunlop]

My 172 has been leaking from the thermostat housing, so i replaced the gasket between that and the head, and when tightening the bolts back up, 2 of the top ones went, one sheered off, and the other rounded off.

is there anyway of fixing this with out taking it back off? dont want to have to buy another ghasket.

 

[Mark One]

you need 2 new bolts (obviously) and if you can get the old ones out then great. If you can't, then I'd assume you'd need to get a new thermostat housing and have a play with a grinder.

 

[dunlop]

its sheered off in the head as has the one thats rounded off.

 

[caister]

Blimey you must have given them some bisto! They hardly require any tightening though thats quite an obvious thing to point out now...

If i'm thinking of the same bolts then the thread come out of the other side of the housing so you could probably just twist them out with some mole grips

 

[lemonnobby]

if ones rounded of see if you can get some moles grips on it take it out then take the houseing off and get the snapped one off.

 

[dunlop]

yea it's stripped the thread in the head my mate has suggested redrilling it to an m10 thread and bolt?

 

[sideways danny]

yea it's stripped the thread in the head my mate has suggested redrilling it to an m10 thread and bolt?

helicoil it. M10 would be massively too big, they're M6

 

[fossie]

Might be able to re-tap the hole in the one where you rounded it off but not sure.....
Im sure there is a kit you can buy to get snapped bolts out.. (think its where you drill a small hole in the centre with a reverse thread screw it in, becomes tight and then start unscrewing the snapped bolt......... dont quote me on how it works lol)

 

[dunlop]

we retapped it as an M8 and its all fine now.

 

[Rob.]

I see this happen alot. The bolts on the thermostat housing don't need to be tight tight.