Advice on cooling system work?

[benVFR]

Any helpful tips anyone can give me?

I have a coolant leak right in the heart of the "V" of my VFR... I strongly believe it is one of the hoses attached to the downstream side of the thermostat as I'm pretty darn sure it does not leak till the thermostat opens... anyway this is apparently a common issue and is almost always an improperly tightened hose clamp.

Anyway I have never messed with the cooling system.. for this job I have to:

- Remove gas tank completely (never done this)
- Remove airbox completely (never done this, just changed the filter)
- Remove Throttle bodies (hoping I can skip this somehow and reach tools through to the hose clamps)

The throttle bodies is the big thing I'm concerned about.. they are all mounted onto a frame together but it looks like a huge mess of vacumn tubes and there is a coolant line running through as well for the fast idle.

I've got everything laid out carefully in the garage, prepared with bags + post it's to mark fasteners, etc..

I'm also ordering all the "must replace" parts as well..

This job still creeps me out. I believe the leak is due to someone else not securing the hoses correctly... (I had the thermostat replaced under warranty a few years ago) Pretty sure it would cost me close to $500 to have someone else do this work and I'm not sure I'd feel so great letting someone else do that at this point as the last two big maintenance items I paid a honda dealer for were not done properly.

But the damn thing is so complex anything I take apart I worry will become a reliability weak point. I have the service manual, etc.. and will be being super careful and taking my time.

Would I be better off draining the coolant right away or should I try and postpone that until I'm absolutely sure I have to do it? I think it's going to be obvious where the leak is, but once I tear it down I will not be able to start the bike... this is a slow leak and there are a LOT of hoses buried in there so I want to make sure I get it.

[qqac]

As you take parts off, put the fasteners back on the item you removed, so you don't lose the fasteners or lose track of what goes where.

In a dirty, greasy environment, Post-its are guaranteed to fall off. If you want to tag things, use white duct tape, and write notes/labels on the duct tape with a fine sharpie.

Before you pull apart hoses, cables, etc. wrap or securely stick a duct tape tag on each end of the connection and code it (e.g., A,A, B,B, C,C) so you know what plugs in where. If you are replacing parts, match up the part and put coded tags on the ends of the replacement part.

[benVFR]

Thanks I will get the white duct tape to label hoses, etc..

The post its are just getting stuffed in the plastic bags I've been putting fasteners in...

I will try to put the fasteners back in though.. in some cases I can't do that.

Looks like I need to drain the coolant immediately.. easier to do it first and if I do have to take the throttle bodies off the coolant is supposed to be drained first. Oh well.. it is overdue for replacement.

[benVFR]

Got a quote of $250-300 to do this.. makes me not as sure.

I already have the fairings off and the gas tank partially removed though...

[qqac]

Don't waver, do the job yourself. Wrenching on your bike will give you a new level of satisfaction and appreciation. And even if it is your first time doing it, you'll probably do a better job than they will. They almost always have fasteners "left over" after reassembly.

[drop]

As you take parts off, put the fasteners back on the item you removed, so you don't lose the fasteners or lose track of what goes where.

In a dirty, greasy environment, Post-its are guaranteed to fall off. If you want to tag things, use white duct tape, and write notes/labels on the duct tape with a fine sharpie.

Before you pull apart hoses, cables, etc. wrap or securely stick a duct tape tag on each end of the connection and code it (e.g., A,A, B,B, C,C) so you know what plugs in where. If you are replacing parts, match up the part and put coded tags on the ends of the replacement part.

also, if you can, take photos at each stage before you remove cables and hoses - this makes it easier to figure out routing pathways and what goes above/below/around what during reassembly. definitely helped me out when trying to reroute 20 or so black unlabeled hoses on an F3...

[benVFR]

Okay.. I ordered the first round of parts and will open it up and then order whatever I need based on what I find..

I don't have the ability to pressure test it or anything but I think the quote I got was low.. after talking to them more (including to a tech) it sounded like a black hole that I might be throwing money into.

The tech I talked to said 4 hours last time.. he put it all back together and then something else leaked and they tore it all apart again.

I can afford to do that several times for what they're going to charge...

[beet]

V4s suck ta work on! But they can be fixed take your time, You will do fine!

[gregp]

Tell me about it! A guy came over with his Magna last night, that supposedly needed an ignition module. He borrowed one form a co-worker, and he thought that the bike was running *better*. I rode it - the bike is running on two cylinders! It definately feels like carburation to me because I can slowly move the choke lever and get all four to fire for a second or two. Then he tells me that "Yea, the bike was starting to fart and fire two years ago. I put it in my shed and didn't run it at all last year..." Pulling a bank of V-4 carbs on a 27 year old bike is not my idea of fun. Been there, done that. The Magna looks to be tougher than the Interceptor I worked on. All of the carb boots are sure to be hard as rocks. I sent him running for some Techron, while I think about whether I am going to do this job or not....

[beet]

I did a new one years ago! Pissed me off took & a long time!

[benVFR]

Thanks for the encouragement guys..

I took the gas tank off Wednesday night and took the intake/airbox off tonight.

The throttle bodies look mind bogglingly complex (thought I was going to be ill actually) but the service manual makes it sound like the removal won't be that bad.. the complexity all comes out together apparently.. just gotta remove 2 hoses and disconnect it from the wiring harness..

I can see the leak through the throttle bodies.. If I had been lucky I'd have been able to tighten some clamps and maybe fix it just like that.. but whoever assembled it last time put all the hose clamps on with the screws facing downwards... so I guess I will be getting real good at doing hoses by the time I'm done, as I'm going to have to detach most of the hoses and pull that middle section out to turn it over to access the leak.

Oh well it's all good.. found some spider eggs on the bottom of the airbox.. a big piece of grass doing some feng shui with the throttle bodies... and a lot of NHIS dirt nestled in the V of the engine. If anything at least it'll all be clean when I'm done.

Gotta give Honda some credit.. it may be really nasty complex.. but there are almost no wiring harness pieces that can be plugged together wrong (they are color coded + different connectors) and they did their best to have different color/diameter hoses as well. Still some of the California emissions crap on the airbox was awful... I wish I'd bought the bike in NH! I thought about modding it to not be a california bike but I think I will leave it alone.. I'd have to make some changes to the throttle bodies and I don't want to touch them.

[benVFR]

Almost ready to fix the damn leak.. my parts showed up friday. I just have to pry the throttle bodies off tonight and I ought to be able to fix the leak..

As I've gotten it apart it looks like there is more coolant then I expected.. it's pretty much everywhere. Who knows if I will have to replace a bunch of stuff.

I had a lot of gunk in my coolant overflow bottle.. the manual says to rinse it with water, which I did... I can't seem to get it all out though.. anything worth trying? It looks like metal flakes to me.

I think I will be changing the coolant more often now that I realize how easy it is.

My coolant bottle is also discolored blue.. for the entire lifetime of the bike I always thought the coolant was blue... it's green of course... but the blue discoloration on the bottle makes it hard to see the level.

So far it's been pretty easy.. glad I am doing it even though it's taking time. I had to buy a 22" long Phillips screwdrive to get at the fasteners for the throttle bodies though. All the screwdrivers I own already were inadequate and couldn't hit the spot to get the viffer off.

[med00F4]

You are doing great. I just swapped motors and it all the hoses pretty much fall into place. They are all molded which makes it hard to screw it up. You might have to adjust your idle and sync when you put the carbs back on. Both of mine were off.

[benVFR]

Got em off last night.. what a mess!

Coolant leak appears to just be loose clamps, but I am going to concentrate on cleaning up everything first..

I hope I don't have to sync the "starter valves". (my bike is EFI) when I put it back together.. that'd be another set of tools to buy/borrow that I don't have.. and certainly wouldn't use frequently if I bought them.

[Kham]

So far it's been pretty easy.. glad I am doing it even though it's taking time. I had to buy a 22" long Phillips screwdrive to get at the fasteners for the throttle bodies though. All the screwdrivers I own already were inadequate and couldn't hit the spot to get the viffer off.

see not so bad. all you really need is little confident.

[benVFR]

Yay.. the two hoses with the coolant residue on them are connected to the cylinder heads. I am going to replace them both as Honda has new part numbers for them.

You can see someone got clever with the hose clamps to make it fun for me.

The upside down ones I can actually get.. I assume they were assembled with the thermostat outside the frame... but the lower large one that feeds the radiator @ 12 o'clock in the picture.. WTF...

[benVFR]

F'n A!

All done and no leaking!

Only catch was I seemed to not have gotten the throttle bodies seated perfectly.. it showed signs of a vac leak the first couple times I snapped the throttle.. but the engine must have sucked them into place... it went away by itself. They were a bitch to press on.