coolant tubes and o-rings

[magfo]

Ok, first post here ever. And first of all, this is a fantastic forum! It´s wintertime and a bit cold at the moment here in Sweden where I live. I decided to start tearing down my Gl1500 -00 in januari hunting a coolant leak showing up during the cold months. I hesitated a few times before I pulled the plug and decided to get going.

Anyways. I need some advice down the road regarding the coolant pipes/tubes on top of the engine. I hope someone can help me out. These two pipes with o-rings on them are going into the thermostat housing and into the engine on either side. Would it be a good idea to slide the tubes into the holes of the engine, fasten the bolts holding the tubes, before I install them into the housing? The manual do not give me any hints about the installation procedure.

The old o-rings installed on the tubes were in bad shape. And most certain was one of the sources were the coolant leak was traced coming from the thermostat housing dripping down from the timing belt cover. Would you install the o-rings according to the picture? No hints from the manual.

Thank you!

//Magnus

[Sassy]

Im following along here as Im in the same situation.
Except I haven't torn into mine yet.
Thanks for bringing it up.
Anything you could share about the tear down?

[klppdx70]

Im following along here as Im in the same situation.
Except I haven't torn into mine yet.
Thanks for bringing it up.
Anything you could share about the tear down?

Same situation here.... I recently pulled the carbs to replace some vacuum lines. Buttoned everything up and flushed/refilled the radiator per WingAdmin's instructions (very helpful). Thought I was in the clear until a few days later when I noticed a coolant drip from the lower right side of the engine. I hadn't reinstalled all the tupperware yet, so I am back in search mode this weekend. One thing I had not done in the initial tear down (which I see the first poster has done in this case) is to remove the fans on each side for better access to everything. I should've done that when I first pulled the carbs, and will do it now. This step was not included in J Martino's excellent writeup (https://www.jmartino.me/goldwing/carb/index.htm), but it makes a lot of sense to do while everything else comes off. If you have anything in particular you'd like to know about the steps involved, let me know and I'll be glad to try to assist with photos, etc since I am already at that stage.
Aside from that- like you I am very interested to follow this thread in case others with more experience have specific insights about the o-ring replacement, etc.

[magfo]

Thank you for the support.
The procedure at finaly getting to the point were I could get the tubes and the thermostat housing out was a time consuming task to say the least. Following Wingadmins ”How to replace your cruise and sub air filters” and the Honda manual it was not that hard in the end. I can give more details about the steps. Let me know. I went from a mindset were i was ”just fixing the leak” to take the whole coolant system on the bike into account (putting alot of time and money into the project). Not to be in a rush or setting up deadlines for a work like this was a promise I made to my self.

What I have read, the tubes/pipes alongside the thermo-housing seems to be a popular place for leaks to occur and much likely was the source of leak on my bike. I´ve found a few threads in the forum were people has mentioned they changed these o-rings out but the procerdure in a more detailed manner has not been told. The installation might not be difficult or complex but i guess it´s a critical task to prevent damage on the new o-rings. Any past experience of this particular task would be very helpful.

[klppdx70]

Thanks Magfo for your reply. I plan to remove the fans this weekend, and I hope that in my case the radiators do not have to come out, considering the relative location of my leak.

Is it fair to assume you could have replaced the o-rings easily without removing the radiators?
Did you replace the thermostat or any other gaskets? I am thinking along the lines of preventative maintenance/replacement of any major items while everything is accessible.

I appreciate and agree with your approach. I am not in a big rush either, and am enjoying what I am learning along the way. Hope the o-rings have solved your issue.

[WingAdmin]

If I saw those O-rings like that, I would:

- Remove the old O-rings
- Clean the outer and inner mating surfaces where the O-rings will contact
- Install the new O-rings on the tubes as shown in your picutre
- Spray the O-rings with silicone lubricant spray
- Optionally smear K-Y jelly (or other water-based personal lubricant) on the rings and inner mating surfaces
- Slide them gently into place, making sure the O-rings are not rolling or pinching

That's my personal technique based on experience, not necessarily what might be mentioned in the service manual (if anything IS mentioned, I'm not sure).

[Sassy]

If your leak is close to the thermostat be sure to check the resin housing seal. There is an oring in there and mine came out appearing nothing like the rubber it was. Brittle, broke apart a mess. Based on recommendations from other members here I replaced the resin housing as well because it was stated they warp from heat cycles over time. Is good there now.

[oldcomputech]

Magnus and all, was it absolutely necessary to remove the manifolds to do the tubes? I too am doing this on my 88. TIA

[magfo]

Is it fair to assume you could have replaced the o-rings easily without removing the radiators?
Did you replace the thermostat or any other gaskets? I am thinking along the lines of preventative maintenance/replacement of any major items while everything is accessible.

The manual don’t call for removal of the radiators to be able to get the tubes out. I decided to remove them when i was searching for coolant leaks. Extra room is a plus on these bikes and removal of the thermo-housing was easier then I guess. Yes, infact, I replaced the whole thermo-housing together with thermostat, gasket, the cover (resin housing?) and sensor. Not sure it was needed but gives me peace of mind. Thank you for the reminder about the oring/gasket Sassy. Mine was also in bad shape but not as bad as yours.

Thank you Wingadmin! I followed your steps and managed to install the pipes and the new housing on the bike yesterday. I used a thin layer of silicon grease on the o-rings instead of spray. I slided the pipes into the bores of the engine and temporarly bolted them into place before I let the other ends slide in to the bores of the housing.

[klppdx70]

Thanks Magfo for your follow up and pictures. Nice work!

I am quite sure this will help a lot of folks.

[magfo]

Magnus and all, was it absolutely necessary to remove the manifolds to do the tubes? I too am doing this on my 88. TIA

A member in another goldwing forum managed to wiggle the tubes out and back in without taking the manifolds out. Not sure though if that person did change the orings at all and how it went on with the tube ends going into the bores of the engine. The result is unknown (https://www.goldwingfacts.com/threads/g ... ak.461954/)

//Magnus

[t2oldbikes]

I did mine on a GL1100i some years ago. After making sure everything concerning them was super clean it was possible wriggle the tube in gently with a coating of vaseline. The o-ring was mounted on the tube and the lip on the tube seated it in the crossover.
I did manage to damage the first o-ring I tied to install but it went well after that except for having to run up to the dealer for another ring.
After doing it I felt the toughest part of the job was scraping the old hardened gasket off the heads' mating surface.