Brake fluid recomendations - 1950's JAG XK140

[gtx6970]

System is all new from master cylinder, All hard lines were removed and flushed with de-natured alcohol. All flex hoses are new. Wheel cylinders are rebuilt with all new seals.

Customer wants DOT5 silicone fluid installed.
Is this a good idea ?

Local tech familar with early Jag's suggested Castrol GT LMA Brake Fluid as a good alternative for a vehicle rarely driven

Thanks in advance for the assistance

 

[Exotexs]

My experience with silicone fluid in the late 1970's was bad. I will never use silicone fluid again. Use DOT 3 Castrol. Your local tech is right.
Ex

 

[LarryK]

DOT 5 silicone is only good for a show car. If this person wants to drive aggressively it will not do the job, unless you buy the Racing Silicone fluids, very costly. All old Jags past and present should have Castrol DOT 4. Dot 3 will deteriorate the rubber seals over time. DOT 4 Castrol is good to both rubber and synthetic seals. The older Jags kits were Dunlop or Girling and these were rubber which need DOT 4. The DOT 5 for show cars only saves the paint if it leaks. You have to thoroghly flush all old fluid out to induce the silicone as it will not mix with other fluids. Acts like water in line. Exotexs LMA is DOT 4.

 

[DrEntropy]

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Castrol LMA.

 

[Steve]

LMA definitely. Silicone can cause all kinds of problems on an older system.

 

[Exotexs]

Larry, my Service Manual dated 1964 says DOT 3. But DOT 4 is fine too. Just stay away from silicone, look what happens to women who inject silicone in their lips and breasts...silicone is poison for people and cars after all is said and done.

Ex

 

[LarryK]

Don't ever spray a silicone can in the garage before painting really screws everything up. Get silicone on paint helps protect a paint job, but try to get it off to touch-up or spray. Yep, silicone is good for screwing things up eventually. Needs to be banned, but it's probably from the other side.

 

[piman]

Hello all,

I have to totally disagree with all that has been expressed.

The point made was:-

"Local tech familar with early Jag's suggested Castrol GT LMA Brake Fluid as a good alternative for a vehicle rarely driven"

Vehicles that are not driven often most benefit from Silicone brake fluid.

I will use no other brake fluid on a road car, and this is with two decades of use. I don't know what experiences you have had but the U.K supplied (U.S. manufactured) has done all it is advertised to do. It is compatible with glycol fluids but the benefits are lost if it is mixed. The ideal is to introduce it once the brake system has been overhauled.

Alec

 

[gtx6970]

As it sits the vehicle will get driven approx 1000, to maybe 2000 miles a year at most. Customer wants to drive it and not have to worry about failure from either the wrong fluid or miixing of 2 fluids causing the rubber components to swell or something of this nature.I am in process of a complete brake system overhaul - with a new master cylinder, all new brake flex hoses , rebuilding all the wheel cylinders with new rubber cups. All the metal lines have been cleaned and flushed . The local tech mentioned is much more familar with these early Jags than I am and he said to use either the OE recomended fluid, or preferably convert it to LMA flud at this time would be best.

 

[piman]

Hello Gtx6070,

I had a look at the Castrol LMA and see that it is 'low water absorbtion' so is probably better than the usual Glycol fluid.
Have a look at this link, for more information on the brake fluid I use (I note it has a slightly higher boiling point than LMA):- https://www.automec.co.uk/pdf_files/brakefluid_answer.pdf

I have used this in my 1962 MK 2 Jaguar quite happily.

Alec

 

[RonMacPherson]

Gee Larry,

don't tell that to my TR6, or my Yamaha FJ1200. I first installed silicone in my 6 back in 87 or so. I lived in Rancho Santa Margarita, California. Worked in Tustin and loved driving over the hills into Hemet, Perris, up in the hills above San Bernardino. Now I didn't use it for competition, but with modified suspension, headers and three Sk carbs it wasn't exactly slow. I NEVER had a problem with the silicon.

I recommend it for the requested application; Especially as it is going into a completely dry system.

 

[jessebogan]

Use LMA .It was made for the car.It is compatible with the rubber seals, and if you flush the fluid every year or two (Like you are SUPPOSED TO) you will never have a problem. This is based on 30 years of fixing british cars.

 

[toysrrus]

Hi There Folks;

I`ve owned several Jags (4 E-Types & One `57 XK140 Rdstr): In all of the above + all the other LBCs I have had; I always used "DOT 4" in all the cars and never had a problem with fading etc etc etc:

My Brit Mech Guru always suggests DOT 5 but only if the entire system has flushed out & or New:

SUMMARY: "You can`t go wrong with DOT 4":

Regards, Russ

 

[Exotexs]

that makes 7 for regular Castrol brake fluid. I wonder why.

Ex

 

[DrEntropy]

Umm... 'cause it WORKS? /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

As Jesse said: 30 years of fixin' British cars.
I've a few years on 'im, but am firmly in the same camp. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif

 

[piman]

Hello all,

most people, but not all, are aware of the need to renew glycol brake fluid regularly, but in reality, how many do?

Incidentally, water will Work. (But not for long)

Alec

 

[LarryK]

I bleed and renew my brake fluid every 2 years, unless I have something sitting too long, then yearly. My competition car's brake fluid is renewed before any track event.

 

[Exotexs]

I was adding Castrol LMA brake fluid to my car and I read the container which says: "Meets or Exceeds DOT 3 and 4 Recommendations".

 

[gtx6970]

Talked to the owner today and we are planning to use Castrol LMA , (his preference )
We work on the car on a regular basis and flushing the system semi annually is not a problem

Thanks to all btw

 

[DrEntropy]

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