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MG Midget and Sprite Technical - Castrol Brake Fluid

Now this is weird...

I was working on the wife’s Altima front brakes. Needed fluid – so off to Pep Boys I go looking for Castrol LMA brake fluid. Found two container sizes – and noticed that the quart size is now marked “synthetic” with some color changes to the label & logo while the pint size displayed the standard logo with no reference to synthetic.

With a brake fluid change coming up for my midget – I am now wondering what change (good or bad...)has been made to my favorite Castrol brake fluid product. Anyone across The Pond notice anything different about Castrol LMA? Label says "improved formula" with a common reference (both sizes) to "..exceeds DOT 3 / DOT 4 specs..."

In the photo - old bottle is on left while new bottle is on the right...Is synthetic trending towards silicone performance?

Retail price does not seem to have changed much if any for the new & improved formula...


Mike P.
Upstate NY



Mike Pelone

It still takes paint off. I haven't noticed any other change either. CJ
CJCharvet

Marketing change is all. Castrol LMA is still DOT 4 (which by definition is Low Moisture Absorption, even though Castrol calls it Low Moisture Activity). Just why they call it synthetic is a mystery - has anyone ever seen a natural occurring spring of brake fluid?
Cheers - Dave
David DuBois

I was kind of surprised to see a sticker on the booster of my mostly unmolested 77 MGB that said to use only DOT 3.

Charley
C R Huff

Well - the gues the theme here is "much ado about nothing"

So I will buy the "new" container and work on the MG brake system this weekend...

Like my marketing professor used to tell me: sell the sizzle, not the steak!

Mike P.
Mike Pelone

Id research that 1st before using mike, castrol LMA is the only brake fluid avialable here in the USA that made from bean oil...if they converted to petroleum based and if your car is 1974 or younger and has not been converted to ray bestous rubber....your rubbers will disolve and turn to chewing gum inside of 6 months


that is some scary news

prop
Prop

"...if they converted to petroleum based and if your car is 1974 or younger and has not been converted to ray bestous rubber...."

By law, any brake fluid that is DOT listed (DOT 3 DOT 4, DOT 5, etc), must be compatible with all seals used in passenger vehicles. The requirements for brake fluids are described within the Federal Motor Vehicle Safety Standard 116, prepared by the National Highway Traffic Safety Administration. Within this Standard, motor vehicle brake fluids are classified as DOT 3, DOT 4, DOT 5, or DOT 5.1 based upon minimum wet and dry boiling points, viscosity characteristics, and in the DOT 5/5.1 case, base fluid chemistry. Further information is contained within SAE J1703 (Motor Vehicle Brake Fluid), SAE J1704 (Borate Ester Based Brake Fluid [DOT 4 LMA brake fluids]), and SAE J1705 (Low Water Tolerant Brake Fluids).

All Brake fluids that meet these criteria are non-mineral oil based (non-petroleum) by specification. Common compositions may include synthetic glycol ethers, borate esters, or silicone.

A problem can occur when DOT 3 or DOT 4 fluid is mixed with DOT 5 (silicone fluid), but DOT 3 and DOT 4 fluids cam be mixed with no bad affects on the system. Cheers - Dave

David DuBois

Dave:

Thanks for the well researched response.
You almost had me reaching for my Periodic Table from my high school Chemistry text book...

When I saw the term "synthetic" I immediately thought of "silicone" which is not what I want. I am sure that DOT 3 and DOT 4 can be mixed with no problems. I have been a convert to Castrol Products for many moons now - and just recently read an article in a Hagerty Classic Car insurance member magazine that discussed the ZDDP additives and expect to try a non-Castrol product available on the east coast produced by Brad Penn Oil Corp. - much more expensive than traditional Castrol products - but where else can you find straight weight 50W & 70W racing oils? - but that's another topic for another thread...

Cheers !

Mike Pelone
Buffalo, NY
aka The Nickel City on the lake
Mike Pelone

except david....

the brits used natral rubber up to 1975, then converted to petrolium based rubber like what the USA uses....if you use USA petrolium based brake fluid with natral rubber seals AKA in your masterclyinders... your seals will desolve and you will get a black slimy goo in the bottom of the master cly. resevoir.

but plant based brake fluid aka bean oil...aka castrol lma will work both ways with out damage to the natral or pertrolium based rubbers


prop
Prop

Prop - If you read the full text of Federal Motor Vehicle Safety Standard 116, you will find that natural rubber is on the list of seal materials that brake fluids are required to meet in order to be marketed for passenger vehicles in the US. There are other brake fluids available, including petroleum based one for use in various other off road vehicles, but these fluids are not covered by the FMVSS 116 and are not approved for use in passenger vehicles (that is not to say that they don't find their way into the wrong vehicles from time to time - I drove a bus many years ago where that happened and by the end my run, I was having to get out and bleed the system so I could get the bus to move). I have heard, over the years that this, that and the other DOT rated fluids would ruin seals in ________ manufactured vehicles (you fill in the blank), but have never seen an actual demonstration of the seals failing. First it was DOT 3 fluids would destroy the seals, then it was DOT 4 will destroy the seals, etc. there is even one person on the MGB BBS who claims that American DOT 3 fluid will destroy the seals in MGBs, but British DOT 3 fluid won't. He steadfastly ignores that the DOT rating system is an American system regardless of where the fluid is manufactured. I had a 1980 Audi for a period of time and had thought about putting silicone fluid in it, but the manual said not to use it. I went into the local dealership and asked the service manager why this was and his answer was--- you guessed it, "because the Germans use natural rubber seals and silicone fluid will destroy them". After I told him that I had heard all of that regarding British vehicles since the 50s and it wasn't true there either, he replied that he really didn't know the answer (guess where I didn't take my Audi for service after that). Cheers - Dave
David DuBois

Mmmm

Well david,

You may have technical theroy, facts, and logic, for your side Ill give you that and cant dispute that....But I have practical real world experiance, $900 worth of master clyinders, calipers, and rebuild kits on my side

Id certiamly be intrested in your theroy as to why all the natraul rubber parts in my brake and clutch system ....(slave cyinder, rear brake clyinders) no longer turn to bubble gum and a black gooy slime, for the first time ever scence using castrol LMA....

its been 3 years scence someone with vast knowledge explained american brake fluid vs british brake fluid,,,scence learning this, I have rebuilt the entire brake system and clutch system and only using castrol LMA and have not had to touch it agian scence, and that was 3 years ago

before I could not get a master clyinder to last more then 3 months...but I was using the everday off the shelf dot3 & dot 4 brake fluids,,,not castrol lma, which is not petrolum based

So I dont know what to say....All I know with casrtol LMA my natrual rubber parts no longer desolve, and turn to a black thick goo, as they did using dot 3 and 4 brake fluids.


prop
Prop

Prop - I would be very hard pressed to come up with an explanation of your experience, and I have to say that practical, real world experience trumps theory every time. I do stand my my statement that any brake fluid with a DOT specification, whether American or British will not have any petroleum products in it, a check of the FMVSS 116 and the various SAE specifications will show that. I also know that this particular subject is a hot button issue and don't want to get into a long winded debate over it (possibly creating hard feelings with others), besides, I have to get ready to leave this afternoon for a cruise to Alaska (really tough job, but somebody has to do it). Cheers - Dave
David DuBois

Oh that is so cool david, I can have my bags packed by 3:00 pm if you got an extra ticket LOL....I am so envious of you....will you be going to churchhill also, I understand thats the best place to see wild polar bears


I have to admit, I carried the debate a bit far myself, sorry about that...you are correct...it really is a hot button issue....

BTW...I havnt gotten a chance to see If I still have that double pumper Su fuel pump...Ill let you know when I find it.....

well have a good time...think of us here in the midwest when you get bored, we are in for a soaking from IKE the storm....expecting 9 - 12 inches sometime this week as it moves thur.

PS... 600 miles wide, they do everything big in texas.lol

prop
Prop

Paul - "I can have my bags packed by 3:00 pm if you got an extra ticket LOL" I'll really make you sick, a week after we get back, we go back out on the same ship for a short (4 day) cruise with a bunch of our dancing friends - we call it the cruise to nowhere because it just goes part way up Vancouver Island and then back down - just 4 days of being pampered.

"will you be going to churchhill also, I understand thats the best place to see wild polar bears"

That's on the other coast.

"...think of us here in the midwest when you get bored, we are in for a soaking from IKE the storm....expecting 9 - 12 inches sometime this week as it moves thur.

That's some storm. It sounds like it will rival the one that was so bad in the early 1900's. I think that I'll stick with earthquakes - things may get broken, but they don't wind up in the next county.

"600 miles wide, they do everything big in texas.lol"

I'll bet that is one they would just as soon have on a smaller scale. Cheers - Dave
David DuBois

Prop, without wishing to reignite this subject, but did you buy all the seal kits from the same supplier?

Could he have had a faulty batch?

Did they came from a local parts place or one of the specialists?

I must admit to never having a problem, and I've used all types of fluid in the past (including silicone), just curious!

Andy
a borris

This thread was discussed between 11/09/2008 and 14/09/2008

MG Midget and Sprite Technical index

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