Coolant pipe allen bolt size?...

[4.2Crew]

Will try and attempt replacing the passenger-side valve cover gasket this weekend... Looks like there is a way to access the bolt from below. Does anyone know the allen size of the 2 bolts attaching the coolant pipe to the side of the head? Seemed like 5mm was too small and 6mm was too big. Want to source the correct (and high quality) allen socket before attempting. Thanks!

[Bigglezworth]

6mm. I took mine out and never put it back in... lol Ensure any gunk and build-up inside the head is removed. Q-tip works well to ensure it's clean.

[4.2Crew]

Thanks!!! This is a HUGE help!!!

BTW, did you get at the bolt(s) from the top, or from underneath?

[Bigglezworth]

All from above. You can't see anything, but it's all pretty easy touch and feel to locate and hold in place while you remove. All work done from above. I used a 3/8 rachet, a 4" extension, and a 6mm socket.

[4.2Crew]

Perfect!... Good info! Thanks!

[4.2Crew]

FINALLY!... The passenger-side valve cover gasket has been replaced. It wasn't leaking per-say, but had just slight weepage last Winter... It probably didn't even need to be changed, but the damn thing became an obsession with me! After successfully and quickly changing the driver-side gasket, I attempted the pass-side and almost stripped the forward coolant pipe allen-head bolt this Spring.

Fast forward to today: The rear coolant allen bolt was accessed and loosened by using a long 6mm allen key. The forward coolant bolt was loosened using a 3/8" ratchet with a modified (shortened) allen socket. The coolant pipe does flex enough to allow clearance... But the combo valve also needs to be tilted back out of the way... Luckily, the three 5mm allen bolts securing it to the back of the head are (somewhat) accessible (after removing one of the EVAP hoses) and need just loosening.

Overall, not too bad... Could prolly do it in 1/3 of the time now knowing the tricks!