Oil Leak down Studs? - Triumph Forum: Triumph Rat Motorcycle Forums
Classic, Vintage & Veteran For Coventry and Meriden Models. Anything pre-Hinckley goes.

 3Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 16 (permalink) Old 09-17-2019, 12:43 PM Thread Starter
Supersport 600
Main Motorcycle: 1977 T140V(J)
Senior Member
 
Join Date: Aug 2013
Location: Midlands, England
Posts: 174
Oil Leak down Studs?

Hi All,
Have been bothered by an irregular oil leak from the front of the cylinder head. Shows up after a ride as oil blown back around the head on the head fins. I always thought that it was the PRT seals going. However, it does not leak everyride. After a ride on Saturday, I had the oil trail in evidence. So, I cleaned the oil off and rode the bike to work and back today. Looking at bike after this, I would say the oil appears to be coming down the two outer rocker box studs. These are the short studs that hold the front of the exhaust rocker box to the head. The nut screws on from below.
Has anyone seen a leak from here before? I am assuming that the hole in the rocker box that receives the stud is a through hole, and that the oil is finding its way down the threads. if this is the case, what is the best way to stop the oil? Use a suitable thread sealer, loctite 243?
All the best,
Andy
AndyT140 is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 09-17-2019, 01:53 PM
Team Owner
Main Motorcycle: T120RT
Senior Member
 
KADUTZ's Avatar
 
Join Date: Feb 2006
Location: in my house
Posts: 4,989
Other Motorcycle: T140V,T140D,T140E,T140J
Andy


While I haven't seen this specific leak I have experienced leaks of a similar style. That is oil wicking down or up threaded fastners.


Without having a rocker box in front of me I do not remember if the stud goes into a blind or thru hole. As oil is leaking down the stud I am going to assume it is a thru hole. As such my choice of sealer on the stud would be Hylomar. A second choice would be a bit of Ulta-Grey (Yamabond, Three Bond, grey RTV's). Loctite 243 or 242 are a blue thread sealant and while use on the nut/stud joint is desirable My personal choice would be something to seal the leak where stud thread goes thru the rocker box.


K

TRIUMPH
"THE WORLDS PRE-EMINENT MOTORCYCLE"
KADUTZ is online now  
post #3 of 16 (permalink) Old 09-17-2019, 04:46 PM
SOTP Vintage Series
Main Motorcycle: T160
Moderator
 
Join Date: Oct 2011
Location: Great Britain
Posts: 6,187
Other Motorcycle: T100, T150
Lightbulb

Hi Andy,

Quote:
Originally Posted by AndyT140 View Post
oil appears to be coming down the two outer rocker box studs. These are the short studs that hold the front of the exhaust rocker box to the head.
the hole in the rocker box that receives the stud is a through hole, and that the oil is finding its way down the threads.
The rocker-box is only the top of the compartment containing the valves, the lower part's in the head and the two parts are sealed by the gasket; it could just be a leaky gasket allowing oil to reach the studs where they pass through ... have you tested the nuts with a spanner, to see if they're tight or they'll take a little tweak?

Quote:
Originally Posted by AndyT140 View Post
cleaned the oil off and rode the bike to work and back today. Looking at bike after this,
A quicker test/result might be the 'talcum powder' one. If you haven't heard of this before: thoroughly wash off all previously-leaked oil; allow all surfaces to dry completely; sprinkle or puff talcum powder over and around the suspect area; start engine and observe the suspect area for a period; any leaking oil will spread rapidly through the talcum powder. If it doesn't leak visibly at a standstill, go for a ride but relatively-slowly (so the talc isn't all blown off) and stop frequently to see the first signs of the leak.

Hth.

Regards,

Stuart

Last edited by StuartMac; 09-18-2019 at 05:06 AM. Reason: Correction
StuartMac is offline  
 
post #4 of 16 (permalink) Old 09-17-2019, 05:30 PM Thread Starter
Supersport 600
Main Motorcycle: 1977 T140V(J)
Senior Member
 
Join Date: Aug 2013
Location: Midlands, England
Posts: 174
Hi all,

In reply to Stuart: Thanks for suggestion with the talc, certainly worth a try out. I did try the nuts, the outer two took a small nip, probably no more than one flat of the hex. The centre nut did not move. So, will observe after next ride and see if that is all it takes!

All the best,

Andy
AndyT140 is offline  
post #5 of 16 (permalink) Old 09-17-2019, 06:37 PM
Formula Extreme
Main Motorcycle: T140 cafe NRE900cc
Senior Member
 
Rancidpegwoman's Avatar
 
Join Date: Jan 2012
Location: London
Posts: 896
Other Motorcycle: Yes
Extra Motorcycle: Of course
Hi Andy,
It could be as Stuart advises, a damaged gasket.
There are 3 studs coming down from the rocker box, the middle one is the only one that has a blind hole, the outer two have holes drilled all the way through the rocker box. This immediately gives a problem as studs were not meant to be used in through holes.
I cannot see a way around having the rocker boxes off to solve this if the oil is seeping down the studs.
With the rocker box off the bike:
The middle stud should be tightened in itís hole until it bottoms out, the resulting pressure pushes up against the whole length of the thread locking the stud in place using the entire length of the thread in the rocker box. When correctly fitted there should be 1/2 to 1 turn of thread showing above the rocker box face.
If you can tighten the stud until all of the threads disappear then the stud will jamb only at one point, where the thread runs out. This puts the entire load concentrated at this point which is close to the rocker box gasket face. There is a likelihood that this concentrated pressure close to the surface will pull the metal up causing a distorted gasket face.

If you double nut the stud(s) and remove it, you can check the gasket face for flatness, and reface it if necessary.

Because it is difficult to tap a blind hole all of the way to the botdtom, there is a chance that the stud will jamb Where the tapped thread in the rocker box runs out above the bottom of the hole. While not as bad as jamming at the top, it still makes for a weak fixing as the forces are concentrated at the jamming point in the bottom of the hole, the rest of the length of thread is effectively Ďlooseí.
To overcome the chance of this happening I remove the first turn of thread at the end of the stud. The stud will then press against the bottom of the hole, loading the entire length of thread evenly, making a strong and secure fixing.

The outer two holes have a real problem, there is no bottom of the hole for them to push against as they are drilled right through. The stud will definitely jamb near the gasket surface when the thread runs out, the rest of the thread is then effectively loose, perfect for allowing oil to work itís way down.
The solution to this is to fit the outer two studs with Loctite 270 studlock.
Clean the head and stud of all oil, coat the stud with loctite 270 and screw the stud in gently until it just starts to tighten, do not pull it down hard. In reality you have glued the stud in place rather than locked it in place. The resulting installation should not allow oil down the threads as loctite 270 is a very effective sealant.
If you ever need to remove the stud again, you will need to heat the stud to release the loctites grip. Trying to remove the stud without heating is likely to rip the threads out of the rockerbox.

Regards
Peg.

+1 on the talcum powder trick (someone also has posted that powdered aerosol foot spray was easier to apply).

Here are some photos showing the poorly designed stud holes drilled all of the way through the rocker box:
Attached Thumbnails
Click image for larger version

Name:	AD526186-1235-4CC9-8967-762A9F8FF43D.jpg
Views:	14
Size:	19.8 KB
ID:	655978   Click image for larger version

Name:	39588B64-DD9D-4788-BEF7-E700C0E320C2.jpg
Views:	15
Size:	19.5 KB
ID:	655980  
Adam M. and Konaflyer like this.

Quick fixes are named after how long they stay fixed, not how long it takes to make them.
Rancidpegwoman is online now  
post #6 of 16 (permalink) Old 09-17-2019, 09:57 PM
Moto Grand Prix
Main Motorcycle: 1973 Triumph TR7RV
Senior Member
 
TR7RVMan's Avatar
 
Join Date: Oct 2013
Location: Pleasant Hill, CA USA
Posts: 2,702
Other Motorcycle: 1964 Triumph Mountain Cub
Hi AndyT140, Yes they go through to the oil space on my '73 Tiger as well as the ones Peg was nice enough to photo.

I've seen these leak. What I do is use a sealant on both sides of washer & threads of nut. I always use Mercedes Benz
001 989 98 20 10 it is a Loctite product only sold through Mercedes dealers.

It is very similar to Loctite 574. Clean area perfectly to bone dry. Gas or a parts wash or acetone. Dry well. Smear on sealant. Install washer & nut. Torque as you normally would. Let cure 24 hrs. If this is the leak, it will not leak now. Does not seal if parts are oily at all!! Wipe off squish out immediately after torqueing.

Then rode test & evaluate leaks. If gasket is leaking also then you need a full box reseal, including the studs. But if it's just the nut where oil gathers this will fix it. Certainly worth a try.

This sealant will work on leaky cyl base nuts as well. I've done dozens to good results. Only do 1 nut at a time.

This sealant is really good for cly base gaskets & covseal rocker box gaskets. It will really stop leaks.

It also works well to glue studs into case such as the 4 cyl base studs & your rocker box studs. Loctite 243 works well here too. Both can be removed with wrench no heating. Heating with heat gun or the like will melt sealant or 242/243 & fastener will remove easier.

When removing boxes or cyl the gaskets will have to be scraped with a razor blade or the like. Pretty much need to do that anyway.

I always grease both sides of valve cover gaskets so they come off easy & often no scraping needed at all.

Both the Mercedes & Loctite sealants are made for metal to metal no gasket use. If you used these for say timing cover it would be very very hard to remove. It's not recommended for gaskets, but at work we used if for 30+ years to perfect results. The gaskets break apart on removal so not to hard.

For metal to metal like timing cover or case halves hard to beat Loctite 518. No leaks, long working time, easy to separate later. But 518 has proved not very effective with gaskets & can allow them to migrate or split. Cures to a softer plastic.

While 574 will permeate the gasket & make it stable & seal well as it cures to a tough plastic like material.

These sealants will assure a no leak motor. Others work too, but I've found these effective & very easy to use.
Don
Konaflyer likes this.
TR7RVMan is offline  
post #7 of 16 (permalink) Old 09-18-2019, 06:26 AM
SuperStock
Main Motorcycle: Triumph Bonneville T140E
Senior Member
 
Boggie's Avatar
 
Join Date: May 2019
Location: Buckinghamshire, UK
Posts: 244
Note, there was a suggestion earlier (now removed) that these bikes have rocker oil feed banjos. My T140e is a little newer than yours but I think we share the same rocker feeds (I believe all 650 and 750s are the same but may be wrong) and these do not have banjos. I presume Stuart was talking about triples or the older 500cc engines?

So, just in case anyone was thinking about fixing oil leaks by replacing banjo bolts: The end of the rocker shaft extends outside the rocker box and the oil feed pipe is sealed around it with a couple of washers (one each side of the oil feed pipe), clamped by a nut. It is quite possible that these can leak and I have had such a leak which took a little while to identify as oil travels well on a hot engine and makes it seem that the leak origin lies elsewhere. In my case, it turned out to be a slightly loose nut but I replaced the washers and whilst it was apart, sprayed through the feed pipes with carb cleaner (quite a bit of crap came out too).

For info, the part numbers (in my T140e book) are:
Feed pipe (x1) 71-3550
Nuts (x2) 21-0550
Washer (x4) 70-1335

P.S. I really like the talcum powder technique Stuart, but have a question: is it easy to clean off a talcum/oil mix paste after cooking on a hot engine, e.g. between the cooling fins?

Cheers,
Ian

Last edited by Boggie; 09-18-2019 at 09:01 AM.
Boggie is online now  
post #8 of 16 (permalink) Old 09-21-2019, 02:49 PM Thread Starter
Supersport 600
Main Motorcycle: 1977 T140V(J)
Senior Member
 
Join Date: Aug 2013
Location: Midlands, England
Posts: 174
Hi all,
Thank you all for all the responses and suggestions above. Managed to get out and do a steady 30 miles or so. Got back and have a few drips of oil coming off the fins. Having cleaned all up earlier, I can see:

1) Drive side outer exhaust rocker box stud has oil coming down the threads.

2) Can also see oil that has been blown around the top cylinder (jug) fin on both sides of the cyilnders.

So, am I safe to assume that:

1) Is oil coming down the rocker box stud. Can try Don's suggestion to use Loctite 574 on washer and nut to do a quick solution.

2) This can only be from exhaust PRT seal?

All the best,

Andy
AndyT140 is offline  
post #9 of 16 (permalink) Old 09-21-2019, 03:13 PM
Moto Grand Prix
Main Motorcycle: 1973 Triumph TR7RV
Senior Member
 
TR7RVMan's Avatar
 
Join Date: Oct 2013
Location: Pleasant Hill, CA USA
Posts: 2,702
Other Motorcycle: 1964 Triumph Mountain Cub
Hi Andy, The leak around fins might be PRT seals as they are prone to leaks. Could also be seeping head gasket.

I would consider sealing stud nut/washer. Then verify that's fixed.

Then go after the other leak. That can be really hard to diagnose & may take several cleanings. The thing is oil blown by the wind can travel fast & far. Be almost invisible until it droplets. Start with very short road test of only a mile or less & inspect. Talcum power on area can help show oil. But might be hard to keep power on in wind. Don't jump to conclusions, do the diagnosis so you know what the leak(s) are.

Also oil from prior repairs, know as residual oil can take days to wick out of the nooks & crannies of motor.

Retorque of head sometimes helps seeping gasket. Always recheck valve adj after head torque.
Don
TR7RVMan is offline  
post #10 of 16 (permalink) Old 09-22-2019, 01:44 AM
SOTP Vintage Series
Main Motorcycle: T160
Moderator
 
Join Date: Oct 2011
Location: Great Britain
Posts: 6,187
Other Motorcycle: T100, T150
Lightbulb

Hi Andy,

Quote:
Originally Posted by AndyT140 View Post
steady 30 miles or so. Got back
Quote:
Originally Posted by StuartMac View Post
'talcum powder'
test
start engine and observe the suspect area for a period;
If it doesn't leak visibly at a standstill, go for a ride
stop frequently to see the first signs of the leak.
Mmmm ... how long did you have the engine on tickover watching for possible leaks before you set off and how many times in that "30 miles or so" did you stop and check possible leak sites?

Imho, your assumptions are only reasonable if you first saw the oil on the drive-side outer exhaust rocker box stud and on the fins just either side of the top of the exhaust PRT but nowhere else. Otoh, if you didn't watch the potential leak sites for several minutes before riding and then rode forty, sixty minutes without stopping, aerodynamics of unfaired air-cooled motorcycles are weird, the oil could've come from lots of places.

Hth.

Regards,

Stuart
StuartMac is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options
All posts must adhere to Forum Rules

Register Now



In order to be able to post messages on the Triumph Forum: Triumph Rat Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter your valid email address, that can receive an automated confirmation message. Otherwise, you won't be able to gain full access.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome