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billspit
06-04-2012, 07:37 AM
I pulled the clutch and brake master cylnders off the Spitfire this weekend after they both started leaking. It looks like the seals had shrunk. I also could not believe the crud outside the cylinders. I'm strongly considering going with silicone brake fluid since this is the second time my paint has gotten messed up. Where do you folks buy your silicone brake fluid. Just pop down to the local FLAPS. Any preference to brands? What's the cost?

NutmegCT
06-04-2012, 07:47 AM
Bill - what fluid was in there? How long? DOT 3, 4, 5.1, brand, etc.?

I'm really interested in this. I've been using 3 in my "weekend driver" TR3 for six years with no problems.

Also interested in what you mean by "crud outside the cylinders". Got any pictures?

Thanks.
Tom

poolboy
06-04-2012, 08:24 AM
6 years might be time for a flush, Tom. I've been trying to change mine about every 2 years. Not switch, just flush out the old with fresh.

NutmegCT
06-04-2012, 08:36 AM
6 years might be time for a flush, Tom. I've been trying to change mine about every 2 years. Not switch, just flush out the old with fresh.

Thanks. I have been flushing and filling, but always using DOT3. So I was interested in what BillSpit has been using, which seems to have caused some problems.

Tom

billspit
06-04-2012, 09:49 AM
I used Castrol LMA religiously until I could not find it the past year or two. Since then I have used Valvoline synthetic DOT 3 and 4 to top it up. I bled the brakes periodically.

No pictures. It's the yellowish gloppy crud that brake fluid turns to. It formed at the end of the cylinder where the locking retainer goes.

I rebuilt these cylinders about 1990, so I guess that isn't too bad.

BTW, when I was cleaning the caps, I just happened to grab a small piece of paper towel, wadded it up and dipped into GOJO. It cleaned both cap like a charm.

I'm just not sure whether to buy Castrol LMA through the mail or change over to DOT 5. I seriuosly doubt I will go through the effort of refurbing the calipers and wheel cylinders.

angelfj1
06-04-2012, 10:14 AM
Bill: This discussion takes place at least once a year, and can go on for days, weeks, months. Oh, don't misunderstand, this forum is for everyone to utilize - just trying to save you some time! :yesnod:

If you do a search of, "Dot 5" or "silicone brake fluid", you will have enough reading for a week. There have been no recent developments regarding Dot5 that I am aware of that would suggest a change in my personal procedure. The only variable that we need to watch is the seal formulations being used by the Chinese, in that they MUST be compatible with the hydraulic fluid that you intend to use. That said, how one keeps track of this is a problem and must be dealt with here by users reports.

Incidentally, I have been using silicone in the TR250 since 1985 and no problem. I flush/replace every 5th year.

Andrew Mace
06-04-2012, 10:25 AM
I'm just not sure whether to buy Castrol LMA through the mail or change over to DOT 5. I seriuosly doubt I will go through the effort of refurbing the calipers and wheel cylinders.Pep Boys was the last place in the Albany (NY) area that carried GT/LMA, and they stopped doing so about a year ago. Recently, though, I bought a case of 12 qts. of GT/LMA on eBay for about the per quart price I'd been paying @ Pep Boys, so I'm set for awhile! :laugh:

TR3driver
06-04-2012, 10:26 AM
Where do you folks buy your silicone brake fluid. Just pop down to the local FLAPS. Any preference to brands? What's the cost?

I get mine @ TRF, P/N SBF32 currently on sale for $24/qt (which ISTR is more than I paid last time, really the "sale" means the price is going up soon). It's practically impossible to find at FLAPS, and when you do, they will probably want twice that price for it.

I've kind of lost track of when I rebuilt the calipers that I moved from the wrecked 3A to my current TR3, but ISTR it was around 1990 or so. I expected the bleed screws to at least be stuck, but they came open like they were brand new, and the seals are still working fine.

FWIW, Dow Corning used to guarantee their DOT 5 brake fluid for 10 years service. (Unfortunately, they don't make it any more.)

TR3driver
06-04-2012, 10:37 AM
I seriuosly doubt I will go through the effort of refurbing the calipers and wheel cylinders.

FWIW, Bill, I have done several conversions to DOT 5 now by just bleeding through the system until what comes out is clean purple (DOT 5) fluid. Worked out fine for me. Did my 80 Chevy that way in 88; junked it in 2005 without ever touching the hydraulics again.

Gliderman8
06-04-2012, 10:37 AM
So if I want to switch to silicon, what is the best way to flush out the old brake fluid? I've heard of some people using alcohol as a flush... what's the proper way to do it?

Got_All_4
06-05-2012, 10:10 PM
I flushed mine with alcohol and I think methanol was recommended. One type of alcohol was not to be used. Could do something to the seals. Then I blow it out with compressed air. That was in my TR3A where I got DOT 5 and 4 mixed up some how. I had to replace the rear cylinders anyway. I did go back to DOT 4 because the new cylinders came with a warning that the warrantee was canceled if DOT 5 fluid was used. However in my TR250 I used DOT 5 in 2002 in a complete rebuild and never had a problem. Except last week I had to push the car out and there was a puddle of fluid on the floor and upon inspection the clutch reservoir was empty. Haven't been able to check it out yet as to what caused the leak. Break fluid is right at the top though.

DougF
06-06-2012, 10:48 AM
I have done the same as Randall on both of my Triumphs and a friends Triumphs and with no problems. Just push the old fluid out with the silicone. When it flows solid purple, you're done.

Geo Hahn
06-06-2012, 11:42 AM
I have done the same as Randall on both of my Triumphs and a friends Triumphs and with no problems...

Me three -- flush until you're bleeding Grape Kool-Aid and button it up.

Helps to pour very carefully to not introduce bubbles. When doing any subsequent work that will require a bleed I top up the reservoir the day before to give any bubbles a good chance to float up & out.

As for buying the stuff, Amazon used to have a real good price but they are currently using a 3rd party so you have to pay shipping, not so good ($22):

https://www.amazon.com/North-American-NA4...0620&sr=8-2 (https://www.amazon.com/North-American-NA40-Silicone-Brake/dp/B001BB1GCI/ref=sr_1_2?ie=UTF8&qid=1339000620&sr=8-2)

Got_All_4
06-06-2012, 09:36 PM
I forgot to post that I get mine at Advance Auto Parts.

Brosky
06-08-2012, 09:21 AM
I've been using silicone for fours years in the TR6 and I'm very happy with it. The TR8 still has the DOT3.

Be careful with the DOT 5 brands and make sure that you do NOT use the DOT 5(X).

big6
06-15-2012, 03:52 AM
Hey Bill,

I was at Advance Auto Parts on RT. 29 yesterday and noticed they have several bottles of DOT 5 silicon brake fluid on the shelf.

DOT 5 was put in my TR6 during the frame up restoration 20+ years ago and still looks clean and performs very well. DOT 5 is in both the clutch and brake hydraulic systems and has never been changed and always had a firm brake pedal.

The part to understand is like DOT 3 and 4 keeps water in suspension DOT 5 does the same with air. Purchase the DOT5 and after bringing it home let it set on the shelf for a week or so allowing the air to rise to the top and no longer suspended. Then be very careful not to shake or splash the DOT 5 fluid when pouring it into your reservoir. When others have commented about “spongy brake pedal feel” after converting to DOT 5 they probably unknowingly installed the DOT 5 with suspended air in the fluid. Once installed with air suspended in the fluid you will never get a firm pedal. The air will never make its way back up to the master cylinder like either DOT 3 or 4 brake fluids. However with a sealed master cylinder reservoir, if the master cylinder reservoir is shaken during driving conditions the suspended air will not find its way into the lines.

Back in 1978 – 79 when Harley Davidson experienced rear brake drag that resulted in the rear brake caliper fluid expanding and pushing the caliper piston out. If continuing to ride not noticing the drag the DOT 3 fluid would expand and escape resulting in catching fire upon contact with the hot brake rotor. This resulted in a federal safety recall. The fix was changing to DOT 5 fluid for the higher boiling point characteristics preventing the fluid expansion due to heat generated by the brake drag. In later models the US built caliper was replaced with a Japanese caliper that did not drag. In reality the Japanese caliper piston uses a quad seal and not an “O” ring to retract the caliper piston. I converted due to the federal safety recall probably more than 100 Harley brake systems to DOT 5. It didn’t take long to figure out how to handle DOT 5 fluid preventing customer complaints of a spongy brake pedal feel – especially on a motorcycle. My preference is cleaning all the metal brake parts with brake clean and replacing all of the rubber parts before installing DOT 5. The rubber parts have absorbed either the DOT 3 or 4 fluid therefore you cannot clean to remove all of the fluid. Also if your rubber hoses have any age they need to be replaced preventing expansion or collapse of the rubber hose resulting in also a “spongy feel” or fluid not returning alter applying pressure. The British car DOT 4 rubber parts are compatible with DOT 5 fluid. Some of the DOT 3 rubber parts are not compatible. Again during the Harley Davidson recall the master cylinder cup and “O” ring as well as the caliper piston “O” ring had to be changed. The DOT 5 fluid would cause the Harley DOT 3 rubber parts to swell.

My understanding is due to air suspension in the DOT 5 brake fluid is why the military decided to discontinue using DOT 5 brake fluid. Transporting DOT 5 by the military in the field without shaking is not practical. This is also why DOT 5 silicon fluid is becoming more difficult to find.

I am presently planning to attend the July 7 SBMOC meeting at the Beacon. See you then...

Terry