Silicone VS dot 3/4 Brake fluid

[flatheadtim]

Want opinions on what you all think on this? The fluids do they both oxidize? at the same rates? Change intervals? Is there any aftermarket dual bore masters (one bore for front other for rear so always have two tires braking if a brake line rupture like modern cars) for P15 out there?: confused:

[55 Fargo]

I am running Dot 5 silicone, with all new brake components,6 years now no issue.

Dot 5 is a little harder to bleed all air out, but very happy with mine so far.

Dual MC, go to ECI brakes, they have a dual mc and some type of adaptor bracket,at least I think they do.

Do some searching on here, others have madeup dual mc set-ups, modding there own brackets.

I know dual mc are safer, and may operate more efficiently, but many or most on here run single pot mc, and lots with added front disc conversions.

Not that it could not or does not happen,have not heard of many mc failures, but it does happen....

[flatheadtim]

I am running Dot 5 silicone, with all new brake components,6 years now no issue.

Dot 5 is a little harder to bleed all air out, but very happy with mine so far.

Dual MC, go to ECI brakes, they have a dual mc and some type of adaptor bracket,at least I think they do.

Do some searching on here, others have madeup dual mc set-ups, modding there own brackets.

I know dual mc are safer, and may operate more efficiently, but many or most on here run single pot mc, and lots with added front disc conversions.

Not that it could not or does not happen,have not heard of many mc failures, but it does happen....

If one blows a line and lose all/most of fluid a good single master is still no brakes!? Thanks for your info found this with it! --http://ecihotrodbrakes.com/chrysler_master_assemblies.html

[55 Fargo]

If one blows a line and lose all/most of fluid a good single master is still no brakes!? Thanks for your info found this with it! --http://ecihotrodbrakes.com/chrysler_master_assemblies.html

I realize this, do the search for detailed swap info to dual mc and disc brakes, plenty of good info.

I do know a majority of us run single pot MCs, and if you get a leak it is not fun, but I have seen a lot of this reported on the fourm. I think even yeas ago, it may not have happened ona regular basis, as the vehicle were used ona regular basis...

[flatheadtim]

I realize this, do the search for detailed swap info to dual mc and disc brakes, plenty of good info.

I do know a majority of us run single pot MCs, and if you get a leak it is not fun, but I have seen a lot of this reported on the fourm. I think even yeas ago, it may not have happened ona regular basis, as the vehicle were used ona regular basis...

I agree, will do the search and the ECI info was very valuable!! I guess a good e-brake/park brake is in good order!!

[oldmopar]

I have used dot 5 silicon in about 6 vehicles and have at least 6 years on 2 of them. Good stuff but I do a complete rebuild on brakes Lines hoses linings wheel and master cylinder. This is the only way to do it with a single mc.

Also be sure to properly adjust you emergency brake.

[Don Coatney]

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=22469

[flatheadtim]

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=22469

Thanks Don. Thats a READ!! I'm dizzy after reading all that!! Can you break it down for me?

I will compare the your breakdown with how I interpret it. I will give you feed back if you want. Tim

[Don Coatney]

Thanks Don. Thats a READ!! I'm dizzy after reading all that!! Can you break it down for me?

I will compare the your breakdown with how I interpret it. I will give you feed back if you want. Tim

Read the book or go ask Hermin Melville if Moby Dick died.

[flatheadtim]

Read the book or go ask Hermin Melville if Moby Dick died.

Hmmm.. Ok... thought you might give me your opinion on "ECI"? Well I read the link twice, interesting. Looks like ECI has currently improved their P15 dual master though!! I talked to Hermin Melvilles great grandchild and he said moby got an infection and died a month after Ahab speared him.

Edited April 21, 2012 by flatheadtim

[chopt50wgn]

The biggest differences between silicone fluids and regular brake fluids is hydroscopics. Hydroscopics is the way a liquid will absorb moisture. Silicones do not absorb moisture, so rusting of the lines internally over time will not happen.But silicone fluid is highly flammable but it will also not eat the paint if spilled.

I have always used DOT4 brake fluid and have never had any problems. It's really up to you what chioce you make,they all work.

[flatheadtim]

The biggest differences between silicone fluids and regular brake fluids is hydroscopics. Hydroscopics is the way a liquid will absorb moisture. Silicones do not absorb moisture, so rusting of the lines internally over time will not happen.But silicone fluid is highly flammable but it will also not eat the paint if spilled.

I have always used DOT4 brake fluid and have never had any problems. It's really up to you what chioce you make,they all work.

Thanks for your input helped me make the decision. I think you meant HYGROSCOPIC, this is why they made brake fluid to absorb water so it wouldnt rust lines with frequent changes. If water (condensate) or moisure gets in a silicone system it won't mix and will rust the lines?? Thing is with silicone it hardly breaks down (oxidizes)?? Maybe I'll stick with the ol dot 4

[OldDad67]

The biggest differences between silicone fluids and regular brake fluids is hydroscopics. Hydroscopics is the way a liquid will absorb moisture. Silicones do not absorb moisture, so rusting of the lines internally over time will not happen.But silicone fluid is highly flammable but it will also not eat the paint if spilled.

I have always used DOT4 brake fluid and have never had any problems. It's really up to you what chioce you make,they all work.

Many state police cars have used Silicone over the years with great success, if it works under their type of usage I know it will work for me. I replace all brake components before putting it in the system. My cars set all winter so I like the idea of less moisture in the system, however with open (vented) mastercylinders your still going to get some moisture. It's a good idea to bleed the system from time to time in my opinion.

[fatFreddie]

Brake fluid can be based on glycol or silicone. Most cars use glycol-based fluid, but many people have started experimenting with silicone-based fluid. There are a few disadvantages of silicone brake fluid. Some of these disadvantages include compressibility, moisture, compatibility, and sealing. This article will discuss the disadvantages of silicone brake fluid.

Compressibility

One of the first disadvantages of silicone brake fluid is compressibility. You don't want any compressibility in your braking system. This will cause your brake pedal to feel soft when you press it. Silicon brake fluid is slightly compressible and will cause this softer pedal more than glycol based fluids.

Moisture

All braking systems have moisture in them. Other types of fluid absorb water easily. Unfortunately, silicone brake fluid does not absorb water. Since the water does not mix with the fluid, it will descend to the lowest point and form a puddle. This can lead to corrosion in your hydraulic system and may impair the functioning of your brakes.

Compatibility

Another disadvantage of silicone brake fluid is that it is incompatible with glycol-based fluids. This means that you will not be able to mix the two types. If your car has used glycol-based fluids for a long time, you will have to flush and reseal the entire system to use silicone brake fluid.

Anti-lock Brakes

Silicone brake fluid also can't be used with many anti-lock braking systems. Most systems are designed to work with glycol-based fluid. If you use silicone brake fluid instead, it may interfere with the mechanical valving found in some anti-lock braking systems.

Sealing

One of the final disadvantages of silicone brake fluid is sealing. Glycol-based fluids are easier to seal because they can't pass through small pores in the system. Silicone brake fluid will pass through smaller pores in seals and gaskets. Therefore, it is much harder to seal effectively.

These are some of the disadvantages of silicone brake fluid. It is slightly compressible, so it may give your brake pedal a softer feel when you press it. Silicone brake fluid also doesn't absorb moisture, so the moisture will form a puddle and may cause corrosion in your hydraulic system. This type of brake fluid is also harder to seal because it is capable of seeping through smaller pores. Before you make the switch from glycol-based fluid, you should consider these disadvantages of silicone brake fluid.

[Dodgeb4ya]

I have used DOT 5 in all my old cars and most customers now want it too. Never a problem except for occasional brake switch failure. Wheel cylinders stay corrosion free with DOT 5. DOT 3 or 4 after a couple years-stick W/cyls!

Here in the NW moisture is a huge problem-It Rains alot!

[flatheadtim]

Brake fluid can be based on glycol or silicone. Most cars use glycol-based fluid, but many people have started experimenting with silicone-based fluid. There are a few disadvantages of silicone brake fluid. Some of these disadvantages include compressibility, moisture, compatibility, and sealing. This article will discuss the disadvantages of silicone brake fluid.

Compressibility

One of the first disadvantages of silicone brake fluid is compressibility. You don't want any compressibility in your braking system. This will cause your brake pedal to feel soft when you press it. Silicon brake fluid is slightly compressible and will cause this softer pedal more than glycol based fluids.

Moisture

All braking systems have moisture in them. Other types of fluid absorb water easily. Unfortunately, silicone brake fluid does not absorb water. Since the water does not mix with the fluid, it will descend to the lowest point and form a puddle. This can lead to corrosion in your hydraulic system and may impair the functioning of your brakes.

Compatibility

Another disadvantage of silicone brake fluid is that it is incompatible with glycol-based fluids. This means that you will not be able to mix the two types. If your car has used glycol-based fluids for a long time, you will have to flush and reseal the entire system to use silicone brake fluid.

Anti-lock Brakes

Silicone brake fluid also can't be used with many anti-lock braking systems. Most systems are designed to work with glycol-based fluid. If you use silicone brake fluid instead, it may interfere with the mechanical valving found in some anti-lock braking systems.

Sealing

One of the final disadvantages of silicone brake fluid is sealing. Glycol-based fluids are easier to seal because they can't pass through small pores in the system. Silicone brake fluid will pass through smaller pores in seals and gaskets. Therefore, it is much harder to seal effectively.

These are some of the disadvantages of silicone brake fluid. It is slightly compressible, so it may give your brake pedal a softer feel when you press it. Silicone brake fluid also doesn't absorb moisture, so the moisture will form a puddle and may cause corrosion in your hydraulic system. This type of brake fluid is also harder to seal because it is capable of seeping through smaller pores. Before you make the switch from glycol-based fluid, you should consider these disadvantages of silicone brake fluid.

Thanks FF I appreciate the time you spent on this answer!! You didnt have to but its reallY!!! Appreciated!!

[fstfish66]

i have been running dot 5 for over 20 years in my 1966 highly modified plymouth,,

i plan on changing over to dot 5 in my 1940 coupe,,,,

DO NOT CONFUSE DOT 5 SILICONE WITH DOT 5.1 SYNTHIC,,,

DOT 5 SILICON IS PURPLE,,, and as stated it wont collect moisture,rot your brake lines,,,or take paint off if it gets on your paint,,

[Plymouthy Adams]

when this stuff first came out it was notorious for staining you plastic reservoir and at a glance would give you a flase impression of a full reservoir..of course that may well have been changed by now..just have not messed with it since.

[Don St Peter]

Seems to be a personal preference. Flatheadtim's post reflects the reasons I went back to DOT 3 from DOT 5 silicone on my 40. "Mushy" feel and "seeping" cylinders were a continuing problem for me with DOT 5

Don

[desoto1939]

When converting from old style Dot3-4 Brake fluid to Silicon Dot 5 you need to flush the entire brake system with denatured alcohol.. This might take a couple of gallons of the denatured alchohol.

You need to have a super clean brake system.

I did this on my 39 Desoto back in 1988 and have been running this ever since. I think the soft brake is still an adjustment situation. You must remeber that our older cars did not have self adjusters on them and did not have disk brakes with floating lining.

The older cars were taken into the garages more often and had service done to them. And since we drive them not as much as was done when they were new we lose site of the feel that something needs to be constantly adjusted such as brake shoes. The linings wear down so need to be minor adjusted over time.

Also do not use old rubber brake hoses and cups. MAke sure you get new and fresh stock when converting to Dot 5.

Rich HArtung

desoto1939@aol.com

[TodFitch]

When converting from old style Dot3-4 Brake fluid to Silicon Dot 5 you need to flush the entire brake system with denatured alcohol.. This might take a couple of gallons of the denatured alchohol.

You need to have a super clean brake system.

I did this on my 39 Desoto back in 1988 and have been running this ever since. I think the soft brake is still an adjustment situation. You must remeber that our older cars did not have self adjusters on them and did not have disk brakes with floating lining.

The older cars were taken into the garages more often and had service done to them. And since we drive them not as much as was done when they were new we lose site of the feel that something needs to be constantly adjusted such as brake shoes. The linings wear down so need to be minor adjusted over time.

Also do not use old rubber brake hoses and cups. MAke sure you get new and fresh stock when converting to Dot 5.

Rich HArtung

desoto1939@aol.com

Not sure about flushing with alcohol. I've heard that it damages rubber.

On the other hand if you flush first and then follow through with replacing all rubber parts as you suggest, I guess it would work out okay.

I replaced everything in my '33s brake system when I rebuilt it: New cylinders, new hoses, new steel tubing, etc. Filled it with DOT5 (silicone) back in '97 or '98 and it has been fine ever since. The only real issue I had was getting them bled properly as the DOT5 fluid seems to hold small air bubbles a lot more than DOT3. You have to be careful when you pour it into the master cylinder or you'll be adding air which you then have to bleed out. Unless/until you get all those small air bubbles out you'll have a soft pedal.

[desoto1939]

Not sure about flushing with alcohol. I've heard that it damages rubber.

On the other hand if you flush first and then follow through with replacing all rubber parts as you suggest, I guess it would work out okay.

I replaced everything in my '33s brake system when I rebuilt it: New cylinders, new hoses, new steel tubing, etc. Filled it with DOT5 (silicone) back in '97 or '98 and it has been fine ever since. The only real issue I had was getting them bled properly as the DOT5 fluid seems to hold small air bubbles a lot more than DOT3. You have to be careful when you pour it into the master cylinder or you'll be adding air which you then have to bleed out. Unless/until you get all those small air bubbles out you'll have a soft pedal.

When I [urchased my silcon brake fluid they also sold me two gallons of DENATURED ALCOHOL. the instrutions told me to flush the entire system with the denatured alcohol to get rid of the old dot 3 brake fluid. They also recommended to replace all rubber parts, cups, outer boots and also the hoses with rubber that will support silicon dot 5 brake fluid.

I would not use straight alcohol. as todd has questioned. I did this back in 1988.

Rich Hartung

desoto1939@aol.com