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post #16 of 39 (permalink) Old 08-20-2008, 03:18 PM Thread Starter
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Originally Posted by ossodiseppia View Post
Pardon me if I am misunderstanding your LOL. Brakes and steering are the two most important safety features of a car. So, guessing at which brake fluid to use isn't a good idea. The last thing you need is for your cars brakes to fail when you need them most (that would be while driving).

Papajam's suggestion about looking at the colour of the fluid is the best place to start. Chances are the seals have been replaced with seals made from more modern materials.
I wouldn't have asked the question in the first place if I didn't feel it was important and Dave in the second post seams really knowledgeable on Alfa’s. The color of the fluid is red and the last time the seals have been replaced was in the early 60's. But it sounds like no one is having any problems no matter what they have used, so I guess I should have asked if anyone has had any problems? All I know is my father had problems when he bought the car and fixed them and I’m trying to avoid them. I did call Centerline and they said DOT4 is fine but he was kind of hesitant and wasn’t really sure about using certain fluids but DOT4 was fine.

Greg ~ 1959 Alfa Romeo Giulietta Spider Veloce 750F
49000 orig. miles,no rust, very original, this car was purchase by my father in 1962
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post #17 of 39 (permalink) Old 08-22-2008, 01:08 PM
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brake fluid

Had my original master cylinder and wheel cylinders resleeved(in brass)by Apple Hydraulics.A note from them read (quote) "These cylinder(s) are not compatible with silicone brake fluid.Use only DOT3 or DOT4 fluid".No explanation was given,but I doubt that it's because the cylinders are brass.I'm using Castrol GT/LMA with no problems in 900 miles.Brakes are great. FWIW,my car had only 600 miles on a complete brake system rebuild(new wheel cylinders,master cyl.,linings,etc.)when the PO parked it in 1989.It was kept outside from 2002 til' I got it in 06' and had to do everything over again,including linings,due to moisture/corrosion.George Kraus may have some input on the brake fluid subject. Regards,Phil 1961 Giulietta Spider Normale
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post #18 of 39 (permalink) Old 12-07-2014, 12:35 PM
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Automec DOT 5

Hi, after some critical issues using silicone brake fluid on my Gulia spider I have detected that one brand don’t suite my setup. This is my observation and I don’t claim you will have the same issue that I do.

During my restoration project 2009/2010 I bought a re-sleeved BMC (bore 3/4”) as alphil describe and bought all new seals for the brake master cylinder, rear wheel brake cylinders and front calipers. All seals new of high quality brand via AlfaStop UK, assume original Girling.

During the restoration project I was reading about brake fluid on several InterWEB forums including AlfaBB and found several topics regards to silicone brake fluid, some negative some positive and I made a decision to go for a test as the car will be driven only a few month during the year and the rest parked in a garage. I was excited to go for Atomec DOT 5 and everything was evolving positive. Bleeding the BMC and brakes was no different than for any other fluid.

In absence of reference to characteristics regards to brake pedal pressure etc. I assume everything was fairly ok and that some “sponginess” was to be expected. Even better the Automec DOT 5 fluid was purple, who can say no to that color!
After a test run I couldn’t feel any problem with the setup and behavior during braking and was happy about my chose to go for DOT 5 (Automec). The Pedal felt firm and solid during pressure and brakes was awesome.

Last summer I was on a road trip on a hot summer day and suddenly lost pedal pressure! The braking pedal vent all the way to the floor. First thought was that the BMC heating shield, protecting BMC from exhaust pipes, had dropped off. After a quick visual inspection checked out OK and intact why I parked the car for 1H to cool down as I expected that I had some overheating issues regards to BMC anyway. Didn’t get any better and “linked home” carefully.

The next day I checked the brakes again a got back some of the firmness in the brake pedal but removed the BMC anyway to check. I found out that both BMC seals was expanded and didn’t understand why as I was using silicone fluid, it shouldn’t happen! Silicone should be the best a car can get.

Did a bench bleeding test on the BMC and got nothing out from it. Ordered a new seal kit for the BMC this time from OKP to hopefully get another brand, just for test. Installed both new seals and the BMC went back to life again.
The BMC has not been in use (exposed for fluid) for that long time as this was back in June this year. This weekend I decided to check the rest of the wheel cylinders and calipers and found that all of them are expanded too. They worked barely and if they stay as-is I will most likely get problems.

So what to learn about this then. My conclusion is that some seals, at least the ones I bought, don’t cooperate with Automec DOT 5 brake fluid and will expand during a year or two and loss of brakes as result. From a personal perspective I strongly recommend to use DOT 4 and from a well-known brand i.e. ATE or Castrol. I personally will go for the ATE racing blue DOT 4 and next time exchanging fluid use Motul RBF 600. The main reason is to see when new fluid gets out of the benders. Both of them has fairly high wet boiling point which is good and for Giulietta and Giulia spiders the BMC is somewhat exposed for heat from the exhaust down pipe.

Finally, this is my personal observation based on the selection of products I have made, nothing else.

Best Wishes,
Joakim
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post #19 of 39 (permalink) Old 12-07-2014, 01:09 PM
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Hi Joakim,

How are you doing?

I have been using the cheap generic Biltema crap (SAE J 1703 DOT 4 +, approx. $8 1 liter)). for many years now in both my Alfas and other daily driver cars and never had any problems.

http://biltema.se/sv/Bil---MC/Bilres...vatska-361751/

Dennis

Last edited by concept 101; 12-09-2014 at 07:50 AM.
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post #20 of 39 (permalink) Old 12-07-2014, 08:52 PM
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I had the master cylinder from my 60 Sprint rebuilt and resleeved approx. ten to twelve years ago by a company that specializes in brakes and I have used DOT 4 fluid. I recently had to rebuild this MC because the fluid ran right past the rear piston seal. These seals had hardened to the point of not sealing against the bore. Now maybe that was the life expectancy of the rubber compound or maybe DOT 4 was the issue. I will give the Castrol GT LMA a try. Thanks, DC
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post #21 of 39 (permalink) Old 12-07-2014, 11:25 PM
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Quote:
Originally Posted by concept 101 View Post
Hi Joakim,

How are you doing?

I have been using the cheap generic Biltema crap for many years now in both my Alfas and many other cars and never had any problems.

Dennis
Hello Dennis, I'm

And it will work for me too but the technical specification B.T announced say wet boiling point to 189 degree C (372 degree F) for the more "expensive" DOT 5.1 and that is fairly low. I might save some money but the cost isn't that much anyway for good quality DOT 4 fluid.

Best Wishes,
Joakim
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post #22 of 39 (permalink) Old 12-08-2014, 04:23 AM
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DOT5 (Silicone) vs. DOT3 or 4

It's been discussed many times..you cannot mix or purge one for the other. All the seals and lines should be changed. Greig seems happy "cleaning" his lines.. but that is a crap shoot. I don't believe the brand has anything to do with it. DOT 3/4 is compatible in any brand only the boiling point and hygroscopics are different. Castrol LMA is favored by racers because it has a higher boilng point and than the generic brands. The all around best (Dot 4) is ATE Blue or Gold which can go as long as 5 years without a seasonal bleed to get harmful water out of the system and is Giulietta friendly . Any new car like, Mercedes Benz doesn't need a seasonal bleed because of this.
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post #23 of 39 (permalink) Old 12-09-2014, 11:28 AM
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we have been using DOT5 silicone brake fluid in all our cars for the last 40 years without any issues. lancia's, alfa's, landcruisers.... Just make sure you rinse the whole system out very well because it is not compatible with other brake fluids, or better replace the fluids when you are overhauling the brake system.
Another benefit other than you never have to overhaul the brakes anymore is that the car will be much easier to push by hand. IMHO this is the best guarded secret the brake industry wants no one to know about. It would collapse an entire industry
oh, and you can smear it all over your freshly painted car as well, it does not attack it like the others.
No business interests, just a very happy convert!!
cheers robin

Lotus Elan plus two 1969, Alfa giulietta spider 1960, Lancia Appia saloon 1957
Lancia Fulvia Sport 1969
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post #24 of 39 (permalink) Old 12-09-2014, 01:27 PM
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I use to make silicone brake fluid in the '80's. We were approached by someone from one of the branches of the U.S. military with a request to manufacturer it to a particular specification.

They were looking for creditable and known manufacturer of silicones (siloxane polymers). We were making space grade silicone adhesives for NASA and the U.S. Air Force so it wasn't a stretch for us. After our formulation was run through numerous and lengthy tests we became a qualified vendor for silicone brake fluid. We made hundreds of thousands of liters of the stuff. The base stock is relatively expensive, so the brake fluid was itself expensive. Even with the initial cost of change-over its cost was justified by the Pentagon because they could show that it extended the service intervals on brake systems by at least a factor of five. Think a fleet of a few hundred thousand motorized vehicles, annual dollars savings in the millions.

Silicone brake fluid's shortcomings were well known and acknowledged; because silicone absorbs gases much more so than glycol based fluid, brakes systems containing the silicone fluid tended to feel "spongy" especially after years in service. We designed and prototyped an on-board vacuum degasser under a DARPA project but the device never made it into more than a few military transport trucks. Water is also not miscible to any significant degree in silicone fluid so when water got in the brake systems the water would pool then rust through components after years of use. We suggested the use of commercially available desiccant systems to forestall the rust. Also, given that it is not water soluble you can have a devil of a time cleaning up a spill.

Then the military pretty much lost interest and we found a small market in fleet operators and car enthusiasts. I had a couple of 55 gallons of military grade silicone brake fluid sitting in my garage for over 30 years; it was left over when we closed down manufacturing. A few years ago I donated what remained to a southern California auto museum.

Never used it myself.

Bob
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Last edited by nunki; 12-09-2014 at 01:31 PM.
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post #25 of 39 (permalink) Old 12-10-2014, 09:33 AM
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Alfisti,

My disassembled '64 Giulia Spider Normale came with a new BMC, but I need to rebuild front discs and rear drums and run lines, so flushing old fluid is not an issue.

What rebuild kits are recommended which will contain seals, O-rings, etc,. that will be compatible with Uncle's favorite, ATE Blue or Gold DOT 4, or bengalcharlie’s DOT5 silicone that won’t eat my new white paint?

Ray

Oklahoma SNO Alfa Chapter Director
'64/66 Giulia Spider finally back in the garage and painted
'75 Olandase Blu Alfetta Sedan 2.0 & '88 Red Milano Verde; both long gone and dearly missed
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post #26 of 39 (permalink) Old 12-10-2014, 01:54 PM
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Quote:
Originally Posted by Raimondo View Post
Alfisti,

My disassembled '64 Giulia Spider Normale came with a new BMC, but I need to rebuild front discs and rear drums and run lines, so flushing old fluid is not an issue.

What rebuild kits are recommended which will contain seals, O-rings, etc,. that will be compatible with Uncle's favorite, ATE Blue or Gold DOT 4, or bengalcharlie’s DOT5 silicone that won’t eat my new white paint?

Ray
They all work fine.. regardless of warnings to use Castrol ONLY on the box. That old British proverb about using Castrol only doesn't apply today regardless of how old the box is. http://www.mossmotoring.com/conventi...e-brake-fluid/

BTW: I usually error on the side of German engineering.. My late model MB would have DOT 5 in it if it was better.. it doesn't. and i don't splash Dot 4 on my cars as a regular policy. If I do water will clean it up . The biggest down side on DOT 3/4 is a leaky cylinder that will patch the inside of a wheel. That can happen. If you can't live with that welll there is always DOT 5 and the down side of it.

Last edited by divotandtralee; 12-10-2014 at 02:12 PM.
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post #27 of 39 (permalink) Old 05-22-2019, 01:36 PM
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Bosch ESI6-32N Brake Fluid (Direct Replacement for DOT 3, DOT 4, and DOT 5.1) Just noticed this product for sale on Amazon. Has anyone have any experience with this product; seems to have good feedback on Amazon users. Longer duration and higher temp capability. Does it do OK with seals in our older Alfas? Here is a link. https://www.amazon.com/Bosch-ESI6-32...ustomerReviews
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post #28 of 39 (permalink) Old 05-23-2019, 05:59 AM
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Quote:
Originally Posted by aenlle View Post
Bosch ESI6-32N Brake Fluid (Direct Replacement for DOT 3, DOT 4, and DOT 5.1) Just noticed this product for sale on Amazon. Has anyone have any experience with this product; seems to have good feedback on Amazon users. Longer duration and higher temp capability. Does it do OK with seals in our older Alfas? Here is a link. https://www.amazon.com/Bosch-ESI6-32...ustomerReviews
Can't see why it won't work or why it is better or worse than any other (unless you are on the race track) .. BEWARE DOT 5.1 is a GLYCOL based just like 3 and 4.. IT IS NOT COMPATIBLE WITH DOT 5.. the decimal point ONE matters

LMA is good and ATE is good and Prestone is good and Carquest is good...and on and on.. They all meet DOT standards and some have slightly higher boiling points or are more or less hygroscopic which allows them to be in service longer than some of the generics.. If you flush your system ever 12 to 24 months they all perform well. If you stretch it to 3-4 years ATE is good ( now only available on shelves as GOLD-- a DOT dictat) ( service periods are MY rule of thumb based on nothing scientific or what the container or mfr says)

I found this on the net...

DOT3
DOT3 brake fluid is the "conventional" brake fluid used in most vehicles.
Advantages:
DOT3 fluid is inexpensive, and available at most gas stations, department stores, and any auto parts store.
Disadvantages:
DOT3 fluid eats paint!
DOT3 fluid absorbs water very readily. (This is often referred to as being hydroscopic.) As such, once a
container of DOT3 has been opened, it should not be stored for periods much longer than a week before use.
Since DOT3 fluid absorbs water, any moisture absorbed by the fluid can encourage corrosion in the brake lines
and cylinders.
DOT4
DOT4 brake fluid is the brake fluid suggested for use in some late model cars.
Advantages:
DOT4 fluid is available at most auto parts stores, and at some (but not all) gas stations or department stores.
DOT4 fluid does not absorb water as readily as DOT3 fluid.
DOT4 fluid has a higher boiling point than DOT3 fluid, making it more suitable for high performance applications
where the brake systems are expected to get hot.
Disadvantages:
DOT4 fluid eats paint! Small leaks around the master cylinder will eventually dissolve away the paint on your
bodywork in the general vicinity of the leak, and then give rust a chance to attack the body of your car!
DOT4 fluid is generally about 50% more expensive than DOT3 fluid.
Since DOT4 fluid still absorbs some water, any moisture absorbed by the fluid can encourage corrosion in the
brake lines and cylinders.
DOT5
DOT5 brake fluid is also known as "silicone" brake fluid.
Advantages:
DOT5 doesn't eat paint.
DOT5 does not absorb water and may be useful where water absorption is a problem.
DOT5 is compatible with all rubber formulations. (See more on this under disadvantages, below.)
Disadvantages:
DOT5 does NOT mix with DOT3, DOT4 or DOT5.1. Most reported problems with DOT5 are probably due to some
degree of mixing with other fluid types. The best way to convert to DOT5 is to totally rebuild the hydraulic
system.
Reports of DOT5 causing premature failure of rubber brake parts were more common with early DOT5
formulations. This is thought to be due to improper addition of swelling agents and has been fixed in recent
formulations.
Since DOT5 does not absorb water, any moisture in the hydraulic system will "puddle" in one place. This can
cause localized corrosion in the hydraulics.
Careful bleeding is required to get all of the air out of the system. Small bubbles can form in the fluid that will form
large bubbles over time. It may be necessary to do a series of bleeds.
DOT5 is slightly compressible (giving a very slightly soft pedal), and has a lower boiling point than DOT4.
DOT5 is about twice as expensive as DOT4 fluid. It is also difficult to find, generally only available at selected
auto parts stores.
DOT5.1
DOT5.1 is a relatively new brake fluid that is causing no end of confusion amongst mechanics. The DOT could avoid a
lot of confusion by giving this new fluid a different designation. The 5.1 designation could lead one to believe that it's a
modification of silicone-based DOT 5 brake fluid. Calling it 4.1 or 6 might have been more appropriate since it's a
glycol-based fluid like the DOT 3 and 4 types, not silicone-based like DOT 5 fluid.
As far as the basic behavior of 5.1 fluids, they are much like "high performance" DOT4 fluids, rather than traditional
DOT5 brake fluids.
Advantages:
DOT5.1 provides superior performance over the other brake fluids discussed here. It has a higher boiling point,
either dry or wet, than DOT 3 or 4. In fact, its dry boiling point (about 275 degrees C) is almost as high as racing
fluid (about 300 degrees C) and 5.1's wet boiling point (about 175 to 200 degrees C) is naturally much higher
than racing's (about 145 C).
DOT5.1 is said to be compatible with all rubber formulations.
Disadvantages:
DOT5.1 fluids (and Spectro's Supreme DOT4) are non-silicone fluids and will absorb water.
DOT5.1 fluids, like DOT3 & DOT4 will eat paint.
DOT 5.1 fluids are difficult to find for sale, typically at very few auto parts stores, mostly limited to "speed shops."
DOT 5.1 will be more expensive than DOT3 or DOT4, and more difficult to find.

Last edited by divotandtralee; 05-23-2019 at 06:10 AM.
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post #29 of 39 (permalink) Old 05-23-2019, 07:13 AM
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If you use DOT 5, do it at the time of total rebuild ……… all new rubber pieces ………. you don't want to use DOT 5 with a system that has any ruminants of DOT 3/4 in it. The two types are not considered compatible. And yes, DOT 5 works well for cars that sit for long periods.
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post #30 of 39 (permalink) Old 05-23-2019, 07:40 AM
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Quote:
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If you use DOT 5, do it at the time of total rebuild ……… all new rubber pieces ………. you don't want to use DOT 5 with a system that has any ruminants of DOT 3/4 in it. The two types are not considered compatible. And yes, DOT 5 works well for cars that sit for long periods.
I think that includes hard lines.. I'm not sure how you would totally flush them out if you were switching. I have no experience on that front but thought it might be a consideration and if it was me i'd always have that nagging at my "anxious button" if I tried to flush with brake-kleen.
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