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Taiamai_Rebel
29th September 2011, 12:09 PM
Hi there, i have currently a blown head gasket on my 1994 GQ 4.2 petrol carby engine, and as i was ordering a new head gasket set, water pump and thermostat, the shop said i should also buy new head bolts as the old ones stretch? Is this true? Also is there anything i should be wary about while attempting this job. thanks

YNOT
29th September 2011, 12:24 PM
Head bolts do stretch so it's best to replace them every time.
You should have the head crack tested and surface machined while it's off the engine, a full head reco would be even better.
Also a good idea to have the radiator reconditioned at the same time.

Have fun torqueing the head down, last time I did one the specs said to tighten the head bolts (all 20 odd of them) down in 3 stages, loosen them all off then do it all again. A bugger of a process.

Tony

patch697
29th September 2011, 12:34 PM
Head bolts do stretch so it's best to replace them every time.
You should have the head crack tested and surface machined while it's off the engine, a full head reco would be even better.
Also a good idea to have the radiator reconditioned at the same time.

Have fun torqueing the head down, last time I did one the specs said to tighten the head bolts (all 20 odd of them) down in 3 stages, loosen them all off then do it all again. A bugger of a process.

Tony

Roger that old mate....................lol

Taiamai_Rebel
29th September 2011, 12:35 PM
thanks for the tip ynot, i'll get the radiator done and head tested while its off, pays to do the job properly. I'm looking forward to this job, some people tell me to get rid of my patrol and update but she's done me good over the last 2 years, so i'll keep her,and get rid or update those people instead. Thats why i joined this forum!!!

patch697
29th September 2011, 12:40 PM
thanks for the tip ynot, i'll get the radiator done and head tested while its off, pays to do the job properly. I'm looking forward to this job, some people tell me to get rid of my patrol and update but she's done me good over the last 2 years, so i'll keep her,and get rid or update those people instead. Thats why i joined this forum!!!

Word of advice....... Never trust a Tojo driver, they only want you to swap side cos there blinded with jealousy & hate, I mean really really hate being shown up by Patrol owners.. (They hate being recovered buy us also..... I have first hand in this....lol)

Stick with us mate, you'll be right..............hahahahahaha

patch697
29th September 2011, 12:44 PM
Word of advice....... Never trust a Tojo driver, they only want you to swap side cos there blinded with jealousy & hate, I mean really really hate being shown up by Patrol owners.. (They hate being recovered buy us also..... I have first hand in this....lol)

Stick with us mate, you'll be right..............hahahahahaha

P.s. The TB42's are renown for doing there heads, so if its got a few K's up & you can swing it, I'd take Tony's advice & go a reco head. It may save you redoing the job in the near future.

yakumo
18th October 2011, 01:59 AM
Generally I'd lube the new bolts aswell, just in case you didnt know :)

albi
20th October 2011, 08:56 PM
thanks for the tip ynot, i'll get the radiator done and head tested while its off, pays to do the job properly. I'm looking forward to this job, some people tell me to get rid of my patrol and update but she's done me good over the last 2 years, so i'll keep her,and get rid or update those people instead. Thats why i joined this forum!!!

ahh thats why you get rid of it and get a landie lol
you only have to replace the head bolts if they are a torq to yeild " ie a stretch bolt" or in other words if the tension is ,say 1st step 40nm 2nd step 60 deg 3rd step a further 60 deg , then these are a stretch bolt and are single use only.

albi
20th October 2011, 08:57 PM
Generally I'd lube the new bolts aswell, just in case you didnt know :)

yeh and that aswell ^^^^^^lol hmmmm lube
under the head of bolt and washer and on the thred .

Ade
21st October 2011, 01:49 AM
Word of advice....... Never trust a Tojo driver, they only want you to swap side cos there blinded with jealousy & hate, I mean really really hate being shown up by Patrol owners.. (They hate being recovered buy us also..... I have first hand in this....lol)

Stick with us mate, you'll be right..............hahahahahaha

'tojo driver'..love that name hehehehehehe

Lahej_sas
18th February 2012, 06:35 AM
Head bolts do stretch so it's best to replace them every time.
You should have the head crack tested and surface machined while it's off the engine, a full head reco would be even better.
Also a good idea to have the radiator reconditioned at the same time.

Have fun torqueing the head down, last time I did one the specs said to tighten the head bolts (all 20 odd of them) down in 3 stages, loosen them all off then do it all again. A bugger of a process.

Tony

i had the same problem and did not test the head sadly it as cracked and the head was ruined totally after using it

BIG PIG
7th November 2012, 08:20 PM
does anyone have torques for the head bolts? as im about to have a crack at the gasket myself

Bigrig
7th November 2012, 08:31 PM
For a GQ TB42

Stage 1 - tighten all bolts to 29nm

Stage 2 - go back to original starting bolt and tighten all bolts to 57-67nm

Stage 3 - loosen all bolts completely

Stage 4 - tighten all bolts again to 29nm

Stage 5 - final tighten of bolts to 64-74nm

Not sure why on the stages, but that's what's specified.

What model is yours mate?

rusty_nail
7th November 2012, 08:59 PM
does anyone have torques for the head bolts? as im about to have a crack at the gasket myself

hey mate, all the info you need is in the GQ Factory Manual.i definately reccomend downloading and having a look. i just put a brand new head on mine and the manual was an invaluable tool to get it back together. are you getting the head machined and valves re-sleeved? or just whacking a new gasket on?

gf0012-aust
31st December 2012, 10:20 PM
A word of advice, don't get recon heads, do it once, do it properly - get an original

some of the aftermarket heads are absolute rubbish and you can almost guarantee that if rewelded they will fail in the same spot. Have seen it happen three times.

and as others have said, buy another set of head bolts - don't reuse your old ones - thats just inviting grief later on. and tighten them in the sequence shown in the manual - again, have seen people who didn't and who "made it up" and then ended up with a cracked head down the track