Hey been thinking alot lately bout the vl cooling system and how poorly done the engine swap was in 1986... Anyway, has any body tried this. Fill the radiator up us normal. Undo bleeder bolts and fill head, TB, etc. with coolant. Tap head and coolant lines to release any air bubbles. Rise the overflow above the head. Tighten top bleeder bolt. Now in theory there should be no air, if not maybe a little. Run the car as normal with heater on. When the pressure relief works on the radiator the overflow is now the highest fill point and any air should be pushed out there.???? Does this make sense. I think 90% of air accumulating in the cooling systems of vls. could be from a dodgy radiator cap. Gravity would pull any coolant above the overflow level. Causing just that little bit of air to build up. Any thoughts??

Hi, I use to work at Holden aa a mechanic when the VLs were brand new. The best way that I found to bleed a VL properly is: - Fill the radiator while the car is on the ground - Leave the radiator cap off - Jack the front of the car up as high as possible, and I mean HIGH! ie: front guard up to your shoulder. (This is the hardest bit - but also the most important!) The idea here is to get the radiator cap as the highest point of the cooling system. - Start the car & turn the heater to the fully 'hot' position & ensure the car reaches normal operating temperature. - Carefully remove the two bleeder bolts. (1 next to the thermostat housing, the other on top of the manifold) - Fill the radiator until water/coolant is flowing out cleanly (no air bubbles) from the bleeder bolts. Once there is no air bubbles coming out of the bleeder bolts, continue to slowly fill the radiator for another 5 mins with the water/coolant coming out of the bleeder bolts. - With water/coolant still coming out of the lower bleeder hole, install the lower bleeder bolt next to the thermostat housing. (careful you don't get burnt with water/coolant) - With water/coolant still coming out of the upper bleeder hole, install the upper bleeder bolt on top of the manifold. (these bleeder bolts just need to be nipped up as they have copper washers & the bolts can strip very easily). You need to ensure water/coolant is constantly coming out while you are installing the bleeder bolts, that way you are assured there are no air pockets in the cooling system. - Making sure the radiator is full, fit the radiator cap - Fill the overflow to the required level - Remove the car off the jack - Enjoy your VL with a 'crack free head' !

yep TONY340 is right on the money there i am also a mechanic and that is the proper way to do it

i normally just cut the bottom off a 3L milk bottle at duct tape it, upside down to the radiator filler neck, remove the bleeder bolts until coolant flows out of them, then put the bolts back in just 2 or 3 threads until bubbles stop coming from the thread, then tighten them. keep it running for 5 - 10 mins with the milk bottle almost full until the level stops dropping / stops bubbling. (all with the heater on full hot)

Yeh.. 600-2L coke bottles do the trick nicly for me.. I also replaced the bleeder bolt with a high tensile bolt and taped the hole bigger so the crappy aloy bolt wouldnt snap on me.

when doing mine i didnt jack the car up i un cliped the radiator and left all hoses hooked up and lifted it just high enough so the filler cap was the highest point then tied it up to the car port doesnt sound to dodgey does it? lol

I use an old radiator hose that ive cut so its straight, jam that in the radiator filler and bleed as mentioned above with the bleeder bolts

Sorry, I'm not a mechanic, just a tuner. So I can only offer a way to benefit from the poorly grafted nissan engine that lives in most VL's. If you want less hassle bleeding the cooling system (two less bolts), make a few more horse power or kilowatts at the same time, with slightly better throttle response. Bypass the Manifold heating passthrough pipes altogether by running a hose from the front of the engine to the back. from memory a 5/8 hose was too large so the next size down fits real tight but is the best option. Naturally, always use your extended funnels, cut down radiator pipes, coke bottles, etc) also. I hope this helps save a few coins from the swear jar as I know that tightening those bleed bolts can be painful once the thermostat has opened.

Quote: Originally Posted by TUXEDO [View Post] i normally just cut the bottom off a 3L milk bottle at duct tape it, upside down to the radiator filler neck, remove the bleeder bolts until coolant flows out of them, then put the bolts back in just 2 or 3 threads until bubbles stop coming from the thread, then tighten them. keep it running for 5 - 10 mins with the milk bottle almost full until the level stops dropping / stops bubbling. (all with the heater on full hot) exactly what i do with a 2 liter coke bottle though, and a big elastic band seals the bottle into the top of the radiator abit better, but best way to do it i recon!

Quote: Originally Posted by bachig24u [View Post] Sorry, I'm not a mechanic, just a tuner. So I can only offer a way to benefit from the poorly grafted nissan engine that lives in most VL's. If you want less hassle bleeding the cooling system (two less bolts), make a few more horse power or kilowatts at the same time, with slightly better throttle response. Bypass the Manifold heating passthrough pipes altogether by running a hose from the front of the engine to the back. from memory a 5/8 hose was too large so the next size down fits real tight but is the best option. Naturally, always use your extended funnels, cut down radiator pipes, coke bottles, etc) also. I hope this helps save a few coins from the swear jar as I know that tightening those bleed bolts can be painful once the thermostat has opened. got a pic?

Quote: Originally Posted by PROGMH [View Post] got a pic? No, it's under the manifold. but if you look at where the water goes in and out of the inlet manifold you can work it out. just be prepared to replace some of the water neck fittings if you discover they are excessively corroded.