Draining coolant

I decided to replace the coolant in my project VF500F, not knowing what state it was in or whether there was any at all.

The problem I had was that removing the drain bolts on the two front cylinders took forever because of the absolute lack of access. I couldn't fit a socket in there, and using a wrench I could only turn it maybe a degree or two at a time before I would have to completely reposition the wrench. And then my fingers practically cramped up trying to unscrew the bolts by hand when they were loose enough.

Is this par for the course? I considered either bending an offset wrench even more, or grinding off a socket to get more clearance. How do the pros here handle the situation? Do you remove the headers?

And, is there a torque spec for the cylinder bolts? Neither manual I have (Honda service or Clymer) provide one. And how would your torque the bolts - is a ground-off socket needed here?

TIA!

 

on many hondas it helps to loosen or remove some radiator screws so you can push it forward for more room. on some early vfs and vfrs the rad can easily push out about 2" and pivots on upper bolts.

 

I think you've gone above and beyond here. IIRC those cylinder head drains only let out the last few dregs that can't drain out though the drain port on the pump housing (if the 500 has that), if not I would have just disconnected a coolant house at the lowest possible point e.g. where it joins the pump housing.

If there is no other specification then follow this table:


If you can't get a torque wrench on there, I would go gently by hand and put some blue loctite on; you don't want or need to strip a thread, the tension is only there to prevent a leak.

 

final step: wash out the system with a garden hose w drains open. check coolant level after first ride.

 

Thank you. I’m putting off the flush with a garden hose right now as I haven’t gotten it to actually start yet. I wasn’t sure if a flush could get water into spots that just pouring coolant wouldn’t displace without a running motor.

 

sure u might also just carry a few gallons to pour in. flushing after draining cooling system is best. might be residue at bottom.

watch for any rusty-lookin debris in the drainage.

 

@Terry Smith thanks- I was just filling the service manuals I had which did prescribe removing the cylinder drain bolts. I would say there was something more than dregs that came out when I removed those bolts- a stream shot out to near the front tire in a nice arc, and this was after I let the bike drain from the bottom drain bolt first.

I should have held off when I realized getting them back in was going to be a PITA considering how hard it was to get them out.

and I was right- I could not even get the bolts started with my fingers. The main obstacle to access is a bolt that looks like it helps hold the engine in the frame. This long bolt is in such a position that it’s nearly impossible to get to the bolt hole straight.

I didn’t want to remove the long bolt without knowing what might happen once it comes out - as I might not be able to reposition the motor if it shifts….

 

radiator bolts ! oem rad hoses are flexible enough to swing bottom forward for access to 2 bolts.

 

Understood. It's my intention to ultimately do a flush, but for now I wasn't even sure there was much coolant in the system at all, nor was I confident about the condition it was in, if the condition of the gas was any indication.

Unfortunately, I couldn't figure out how to thread the screws in time to even fill up the coolant, so it's sitting pretty much dry of coolant until probably next weekend. Hopefully that isn't a problem.

As for the radiator - I didn't feel like the rad was preventing the access (I recall the bottom of the rad is located well above the spot I'm trying to get to), but I'll definitely check it out next time! I did feel like the problem was the bolt through the frame just forward and below the drain bolts. and the frame itself. Those two conspired to make it hard to get access with a tool or fingers.

I might put it on my abba Skylift which means at least I won't be lying on my back while I'm working and swearing.

 

I feel your pain mate. BTDT on a few bikes, sounds like refitting the exhaust stud nuts on a Vespa 300 which requires you to work upside down and round a corner under the bike. Have you looked at whether a wobble bit would make the job easier? You can also use standard sockets with a wobble extension bar.

 

Thanks @Terry Smith . Indeed - I’m going to look at those wobble socket adapters. Because of the extra space they add at the socket end, not sure if they will work - but they’re not expensive and seem useful to have around.

My Wera socket set has a wobble extension, which doesn’t take any space at all at the socket end, but it doesn’t wobble enough to get in the spot. But my biggest challenge isn’t just turning the bolt - it’s getting the darn bolt started in the hole!

I have a feeling I’m going to be removing something to do this if @squirrelman ’s suggestions to move the rad doesn’t help.

 

Can you use a piece of rubber tubing over the bolt head as a flexible driver to get started?