Thruxton R Barrel Fault Hairline Crack Or Porosity Leaking Coolant

Sounds like coolant then? A poor barrel casting.

 

Hi timboo, I have not heard of any failures of barrels on 1200 Bonneville engines leading to coolant loss, nor any modern Triumph engine come to that, other faults yes but not the one like yours. Like Baza says it sounds as though it's a casting fault. It is a fairly straightforward job, head and barrels off and replace barrels and build top end back up, I guess the part will have to go off to Triumph first for inspection and the dealer given the ok to carry out the work, given it is an expensive job, if that is the case insist your dealer give you a loan bike as it is likely to take some weeks. At least you did not buy it private and it is under warranty, I would estimate a price of around the 2.5k for parts and labour. Let the forum know how it progresses.

 

And another break-in period will be required no doubt.

 

I know the right way to correct this fault is to replace the defective part but it may also be feasible to rectify the problem insitu.

I don't know what material the barrels are made from but would suspect a ferrous material rather than ally with liners.

What appears to be the problem is a failure of the coolant jacket to the engine. The walls of which are not subject to very high pressures but do endure large temperature cycles.

Once the coolant has been drained it should be possible to identify the location and extent of the failure by the use of penetrant dye as used in NDT examinations. Once the nature and magnitude of the failure is known it may be possible to effect a local repair by grinding out and TIG welding the crack.

My thoughts are based upon a repair I carried out on the oil cooler of my Ducati after I had errantly ripped the fixing bracket off and breached the lowest gallery of the cooler. Having discovered the cost of a new part and sought the advice of many so called radiator and oil cooler specialists, even going the Bicester Heritage where they manufacture one off coolers for Warbirds I decided to have a go myself. The problem was that the cooler is made of aluminium and wall thicknesses are not great. The bracket was spot welded to the the lowest gallery,

My repair was effected by thoroughly cleaning with brake cleaner and drying the damaged area, drilling a hole through the "L" bracket and both walls of the lowest oil gallery, liberally applying good old Araldite to the bracket and external faces of the oil gallery and then blind riveting the bracket on using a stainless steel pop rivet which not only fixed the bracket on but sealed the oil gallery by locally pinching the walls together.

As the engine is air/oil cooled, no plumbing on the machine , my concerns were that I had irreparably reduced the effectiveness of the oil cooler, such that oil temps would be abnormally high but no such evidence has been forthcoming and the author of this thread has actually seen the machine in use.

 

If they won't recover an unrideable bike under warranty then tell them you're happy to take it to a dealer of your choice and they will bill the original dealer direct for any work done, that should get them moving

 

Hi timboo, if your machine was purchased as a used Triumph approved machine, then it comes with a 12 month warranty and as such should be covered at any Triumph dealer, however I would insist that the dealer you bought it from collects the machine and carry out the inspection and any repairs, if their response is unsatisfactory then enter into a formal complaint via the Triumph UK website, they are quick to respond and Triumph will make contact with the dealer and e mail you on progress, it is not your responsibility to go and chase up recovery to the dealer, nor stand the cost. The 1200 barrels are alloy, therefore you can use TIG or MIG welding, TIG welding is ideal for repairing broken fins on cylinder heads, holes and cracks in crankcases and can be used to build up castings with pieces missing. The weld can be machined, drilled, tapped and polished. However MIG welding is generally used on larger areas such as welding heavy gauge aluminium plate and not suitable for alloy cylinders, using the TIG welder less heat is produced during the welding process, reducing the risk of distorting. There are a number of issues to consider when deciding to repair such a task as yours, and unless you are proficient with TIG welding then I would respectfully suggest do not attempt the repair, you will need to drain the coolant, then prep the area first by grinding the area, or other suitable method to remove the coating, then thoroughly de grease the area, once welded you will need to clean the weld up, then repaint the area, however any repair will reduce the machines value, and if you sell your machine at any point you have to be truthful in the description and any disclosure (if you are asked about any history of repairs or faults, past or present), the last thing you want is a CC claim for reimbursement. The good news is your machine appears to be Triumph approved and as mentioned if no satisfaction from your dealer then go straight to Triumph direct, good luck and keep the forum updated. Ride safe all from an ageing Rocker.

 

Many thanks Iceman. A superb definitive assessment of the problem at hand. Timboo called me yesterday and he appears to be taking this in his stride. I would be bloody fuming.

 

Definitely worth doing that. Email has a quicker turnaround, is easier and just as admissible

 

Are you happy to name the dealer that sold the bike to you? You'll know this, of course, but...

"An Approved Used Triumph motorcycle is our assurance that all bikes have met our meticulous standards before they reach the showroom. To the customer it is a new bike – so it should feel like one.

Every approved Triumph pre-owned motorcycle includes the following:

-1 Year unlimited mileage warranty*
-1 Year Roadside Assistance**
- Certified Vehicle Quality check
- Full Service History
- 1 Year MOT
- Vehicle History and Mileage Check
- Finance available"

 

Very interesting. What was the caveat on the first item?