I would think that an air lock on an 8V71 in a 4106 would occur in the top (towards the builkhead) cylinder head. As the engine was filled with water, it would push the air up into this cylinder head. Is there a petcock somewhere on this cylinder head or thermostat housing? Jack.
Hi Doug is there not also a engine manual? You didn't mention it in your list of manuals. The engine manual is very detailed, and while it doesn't cover all aspects of the engine (some of which are covered by the coach manual) it definitely covers some things that the coach manual lacks. I have a separate pdf of a manual that covers the 4-71 and 6-71 in all it's road applications truck, transit and coach and this is the one that covers the cooling fan hub and other specifics of the cooling system not mentioned in the coach manual. Out of curiosity is this the case with your manuals?
Quote from: zubzub on February 05, 2009, 06:54:41 AMthis goes way back to the beginning of the thread but I thought I would mention it. On a 6-71 there is apparently a vent that can be opened on the top of the thermostat, this is done when refilling the cooling system. I came across this last night while studying up on my engine. Someone here hopefully can confirm that 8V71s have this as well? Also, I have a pdf of the maintenace manual for coach and engine of my 4104 which I had printed for ease of reference. I'm pretty sure I would be lost without it. If you do decide to keep this bus, try to get hold of the books for your bus. Zimtok was the original scanner for my books (thanks again Zimtok) but that was a labour of love as he has a 4104. Maybe someone here has the 8V71 book scanned? I have always used factory manuals to help me stay on top of my old vehicles, they don't show everything but they help, and also can be used as reference points on these long complicated threads.Quote from: JackConrad on February 05, 2009, 07:07:27 AM I would think that an air lock on an 8V71 in a 4106 would occur in the top (towards the builkhead) cylinder head. As the engine was filled with water, it would push the air up into this cylinder head. Is there a petcock somewhere on this cylinder head or thermostat housing? Jack.Yes on most of the 8V's in GMC's, there is suppose to be a petcock to expel the air on top of the thermostat housing. Sometimes I've found it on the back of the surge tank, where a line goes from the top of the thermostat to the upper back side of the tank.Unfortunately, I had Doug look for one in both places, and it's been removed. I then had him remove the line from the top of the housing and he reported that only coolant came out... no bubbles.This now makes sense after looking at the photo's he sent me. The upper radiator hose is suppose to go from the thermostat housing to the top of the radiator... if you look in the pictures I posted on here... it's actually drooping like it's headed south.I'd like to know where the upper hose from the radiator is routed. Oh, and Doug, Yes, I'd like a copy of your CD manual. Very Much, Please Please Please Please!Dallas
this goes way back to the beginning of the thread but I thought I would mention it. On a 6-71 there is apparently a vent that can be opened on the top of the thermostat, this is done when refilling the cooling system. I came across this last night while studying up on my engine. Someone here hopefully can confirm that 8V71s have this as well? Also, I have a pdf of the maintenace manual for coach and engine of my 4104 which I had printed for ease of reference. I'm pretty sure I would be lost without it. If you do decide to keep this bus, try to get hold of the books for your bus. Zimtok was the original scanner for my books (thanks again Zimtok) but that was a labour of love as he has a 4104. Maybe someone here has the 8V71 book scanned? I have always used factory manuals to help me stay on top of my old vehicles, they don't show everything but they help, and also can be used as reference points on these long complicated threads.
talking through my hat here but looking at the pics from Doug and Barn Owl, Doug's looks like one of those emergency rad hoses with the internal spring so they don't collapse when they are bent. They create a lot more resistance than the one in Barn Owl's. Also while there is no pet cock on Doug's thermo housing there is the small coolant line where it should be, but as Dallas had you crack that one? weird how the coolant line heads south like that. Where is a bus nut when you need one?? Probably the El Paso ones are wintering in Guanajuato.
Question for you Dallas. Should this bus have power steering? I got quite the workout driving her and I think my biceps grew several inches in the time I drove her. Looking at the engine picture, I am pretty sure I see a power steering pump on the right, but maybe not.
Doug, Yup,It should.DallasQuote from: BigDougInOregon on February 05, 2009, 07:56:43 AMQuestion for you Dallas. Should this bus have power steering? I got quite the workout driving her and I think my biceps grew several inches in the time I drove her. Looking at the engine picture, I am pretty sure I see a power steering pump on the right, but maybe not.
Just gets better and better.
The good news on the power steering is that it's power assist (pretty sure) so it won't be too hard without. The other good news is you're strong enough to drive it without, must be all those kids hanging off you ( I know mine keep me strong). The PS is probably out of oil or something, the least of your worries. The other good news is that once you have the power back you will really enjoy it.
Quote from: BigDougInOregon on February 05, 2009, 08:50:22 AMJust gets better and better.What, your biceps? Or the power steering? God bless,John
About the oil sample, SPEEDCO will do one , takes around 3 minutes. They will also supply you with the bottle. Steve 5B....
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Topic: Update from Doug with the PD4106 (Read 149753 times)
