Jump to content

Coolant Leak At Head Bolts


r100gs
 Share

Recommended Posts

I installed a Low Compression Head from S3 on my 2013 ST300. I am now having coolant leak from around the six copper washers under the six head bolts.

 

At reassembly: I did NOT use Loctite on the bolts, I reused the six copper washers, I heated the copper washers with a torch (the washers were laid flat on my concrete garage floor) until red hot, I used a top quality torque wrench and tightened the bolts in multiple steps using the crisscross sequence until tight at 84 in/lbs.

 

I ran the bike the first day for 20-30 minutes and all appeared okay.

 

The next time I looked at the bike I saw coolant at a couple head bolts. I started the bike and then saw more coolant leaking from multiple head bolts.

 

I shut off the bike and found the head bolts to be loose. I tightened each bolt as best I could without removing the air box, radiator and other parts. I then rode the bike for 30-40 minutes without any more coolant leakage that night. 

 

The next day I checked again and found the head bolts to be loose and coolant around multiple head bolts.

 

I have tried to search the forums for a solution and found one result but I could not determine the fix by reading that search result.

 

Thanks in advance for the advise, critique, help, etc.

 

Happy New Year to all,

 

Chuck

Link to comment
Share on other sites

 

 
 

*Where did you find the head bolt torque figure, it sounds very low to me- Page 29 of the "Sherco Top End Maintenance Manual" and Cylinder Head[nuts or bolts] 7 lb/ft, 84 lb/in (10 n/m) from Copemech.

*Did you change the o rings? - No. The new Head came with a new "o" ring that I did use, but I used the original larger outer "o"ring as I did not get a replacement "o" ring with the order. 

*short allen key- my head bolts are 8mm hex head bolts that screw down into the cylinder. I did use a small 8mm wrench and a 1/4" socket wrench to retighten the bolts after the first leaks. 

 http://www.shercousa...t2.cfm?action=9 This Link has the listing of Sherco Manuals and Parts up through 2014 and at the bottom of the page is the Link to the "Sherco Top End Maintenance Manual". Page 17 of this Manual shows on Picture 24 small "o" rings for each of the six head bolt studs. My head bolts did not have these "o" rings. I tried calling RYP today but they are probably out for the weekend. I will send them an email to see if I should have these smaller "o"rings.

I will probably retighten the bolts the next chance I have. That might be a few days from now though. I will post RYP,s response next week and /or give future updates as I work on the problem. 

Thanks, Chuck

Link to comment
Share on other sites

 

To anneal any solid copper item, I do solid copper head gaskets on the ould bikes, ye need to hang 'em from a loop of wire in order to get to cherry red right through, then quench the item immediately in cold water. You have inadvertently put hard washers back on.

Dick.

  • Like 1
Link to comment
Share on other sites

 

To anneal any solid copper item, I do solid copper head gaskets on the ould bikes, ye need to hang and#39;em from a loop of wire in order to get to cherry red right through, then quench the item immediately in cold water. You have inadvertently put hard washers back on.

Dick.

 

Could I remove the copper washers, do the process correctly and then expect the washers to work properly or should I get new washers?

Link to comment
Share on other sites

 

That 2003 cylinder has studs in it that have o rings on ,where as the design of your cylinder has female threads for a retaining bolt that passes through the head if there should be o rings on those bolts then you should have a shallow recess in the cylinder or the head in which they sit in order that they can form a seal.

 

I will look at the stock head. The cylinder top is flat with no recesses. I will take the top back off to confirm what I recall. 

 

Thanks again

Link to comment
Share on other sites

 
 

10nm = 89 lb/in

I would get new washers and O-rings from Ryan and do 90 inch lbs and call it good.

That is what I will do. I removed the bolts and washers this evening. I will get some silicone grease also.

Should I put Blue Loctite on the bolts?

Link to comment
Share on other sites

 

Just had a thought,if your head bolts are too long or the copper washers are too thin; then what could happen is that the head bolts will reach the bottom of the blind retainer hole and tighten against that and not against the copper washer properly.

This may be caused by an error in the casting/machining process that would not be noticeable on a visual inspection but is a quick fix by shortening the head bolts a little.

I am not saying that this is your problem; but that if the leaking of coolant persists after fitting the 2 new o rings and new copper washers; then this would be something to investigate.

Link to comment
Share on other sites

 
 
 

The bolt length appears to be correct. I put a couple bolts in without the washers and did not have the bolts bottom out. I have a few parts that need ordered so I will get replacement copper washers with the order.

I was at the TSC hardware today and saw a package of Nitrile "o" rings 1/16" thick x 5/32 ID x 9/32 OD. I put these under the old copper washers and carefully tightened the bolts, put the bike back together and went for a 15 minute ride. As of this evening no coolant has leaked. I will recheck the bolts tomorrow and report back.

Link to comment
Share on other sites

 
 
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...