What is the reaction that makes "BARRS leaks" work

[mart]

Yesterday I was discussing trying “Barrs leaks” (BL) to resolve a suspected head gasket leak. I thought about the best way to do this to give it a good chance of working.

I considered possibly putting two lots of BL in to just the engine, after taking the rad out of the system to prevent clogging the rad up with double strength . The idea would be to somehow connect some metal pipes to the hoses, including a filling point and a vent pipe. Then, after running the engine for a short while, let some of the mixture out (hoping that the gasket has been sealed) and then reconnect the rad into the system.

During the discussion, a colleague was of the opinion that BL stays active in the system and if a leak occurs later (in the rad for example) it will be sealed up by the BL. I asked him what it was that caused the BL to seal when a leak occurred, and he said “air and the heat”. I am not sure I agree with this theory as there is always air in the top tank of a rad/exp bottle.

Does anyone know for sure what makes this chemical work, and whether it does indeed stay active in the way inferred? If it does stay active, how come the air in the top tank of the rad does not cause it to solidify?

 

[rtbcomp]

Google "Barrs leaks" there's a lot discussion.

 

[zardoz]

I forgot about the old Barrs leak remedy, till it was mentioned the other day. I only recall using it once, it did work though.

 

[fingers99]

Personally, I'd do a compression test (find out what is really happening) and -- unless the car was a complete and utter shed -- fix it. But, then, I have very little faith in additives.

 

[andypocock]

Jaguar used to "fit" Barr's Leak at the factory in the 60s.

And that was the luxury end of the market!

 

[fingers99]

Jaguar used to "fit" Barr's Leak at the factory in the 60s.

And that was the luxury end of the market!

Well, the cheap luxury end of the market (Jags were always good value because they were built down to a price)! Not something you'd catch Alfa or Ferrari or Aston Martin doing.

 

[zzr1200]

Jaguar....luxury....

British Leyland of the 60's couldn't make a luxury if they had tried, the only luxury vehicle they made was the first Range Rovers, a posh farmers Land Rover.

 

[Justme]

Barrs for rad & hose minor seepage not blow head gaskets. Save your money & fix it right first time round.


Justme

 

[jimmy shoes]

umm what is "barrs leaks"?

 

[wyn]

This is the stuff.

 

[jimmy shoes]

ahh right thanks

 

[hotrodder]

First question, what makes you suspect the head gasket? What symptoms have you got? What engine? A compression test will give an insight into the engines health, a 'leak down' test would be even more beneficial

 

[mart]

What is a "leak down" test, and how is it perfomed?

 

[jimmy shoes]

i think there's a test where you put a solution into a hydrometer, put the hydrometer in the radiator expansion tank and the solution will react to the exhaust gases, cant remember what it's called though

 

[fingers99]

Leak down test involves popping and adaptor from a air compressor into a cylinder with a guage in line. Essentially you can measure how much/how quickly the cylinder looses pressure and generally hear where. You can stop the crank rotating so you can test at TDC and at any point along the bore.

Wonderful diagnostic tool, but probably more than you'd really need to diagnose a HG issue.

As I mentioned, a compression test or, better, a coolant pressurisation test (you pump 1 bar of pressure into the expansion tank, check for leaks/pressure loss, then run the engine -- if the dial moves up and down you have combusion gases entering the cooling system = HG failure) will do it.

Generally symptoms of HG failure are mayo on the dipstick (quite often mayo on the oil filler cap is misleading), rough running at idle and low revs, water loss which cannot otherwise be explained (leaky pressure cap, general leaks, leaks from water pump -- often this won't show until the engine is up to temperature, air lock in system). Often a compression test will reveal a low compression on two adjacent cylinders.

Hope that helps a bit.

What engine is it?

 

[andypocock]

Jaguar....luxury....

British Leyland of the 60's couldn't make a luxury if they had tried, the only luxury vehicle they made was the first Range Rovers, a posh farmers Land Rover.

I don't think there was too much wrong with the design. For 1968 the XJ6 was one hell of a fast luxury car. Unfortunately they were thrown together.

The Range Rover was luxurious for a 4x4 but it was no limousine - I'm not knocking, I run a P38 which was bought as a replacement for a classic. I've done 40K in each.

A few P5 and P6 owners might think their cars were worth a luxury vote.

But I agree that BMC / Leyland build standards finished the British car industry.

 

[andypocock]

Barrs for rad & hose minor seepage not blow head gaskets. Save your money & fix it right first time round.


Justme

Absolutely. Only one fix for a blown head gasket - a new one after a careful check of the head

 

[zzr1200]

I don't think there was too much wrong with the design. For 1968 the XJ6 was one hell of a fast luxury car. Unfortunately they were thrown together.

I totally agree..

The Range Rover was luxurious for a 4x4 but it was no limousine - I'm not knocking, I run a P38 which was bought as a replacement for a classic. I've done 40K in each.

There's not a lot wrong with the classic Range Rover, reliable and fairly simple good basic engineering.
The P38 has several faults without doubt (I also own one), but I think its down more pushing the limits of design when the vehicle was first designed (read not enough product testing and build pricing)

A few P5 and P6 owners might think their cars were worth a luxury vote.

Wasn't the P5 designed before British Leyland obtained control of Rover and the P6 was probably on the drawing board before BL took control and there fore cheaper to finish???

But I agree that BMC / Leyland build standards finished the British car industry.

The lack of standards, I feel were caused more by lack of investment by the goverment, the unions at the time had a great deal to answer for (I remember the days of the long stikes at BL and Fords), the old factory site designs didn't help either and the same thing has now happen at Fords in the UK over the years.

There won't be any major car plants in this country within 10 years, not that theres many now!!!!!!

 

[stinkbridgenine]

I don't think there was too much wrong with the design. For 1968 the XJ6 was one hell of a fast luxury car. Unfortunately they were thrown together.

still to this day,the preferred choice of the unlimited banger racer

 

[stinkbridgenine]

Jaguar used to "fit" Barr's Leak at the factory in the 60s.

And that was the luxury end of the market!

believe it or not, it`s still (well not that brand) used in new/modern vehicles.
how do i know?? cos i`m instructed to do it by the top brass: