What do you think they are off of? I need to get new parts and I want to make sure I get the correct stuff. Surprisingly, a 14" road wheel clears them. At least I was surprised. Thanks in advance.
Can you Identify These Brakes?
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Thrashingcows
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Looks like the style used after 69...70 and up.
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It appears to be the "slider type" used on '73 - '76+ Dodge / plymouth "Aspen" model vehicles. These are totally different than the pin type used on earlier ('68 - 70 Dodge/Plymouth "B" bodies). Later editions of the slider type brake calipers used a "bakelite" material for the single piston. This refuced the corrosion of the steel plated piston. They still use the square section "O-rings" as the secondary piston seal; the primary seal is still the bore ID to piston OD clearance dimensions. Just my opinion of course.
BOB RENTON
I remember the recall for those plastic pistons back in the 70s, early 80s. They would stick and not release, causing poor braking and a steering pull. That's the same thing mine is doing, so I think I'll order new calipers and wheel cylinders, replace the lines and MC and then use silicone fluid in it.
Thanks for the info!
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I have the pin calipers on my RS23VOA****** GTX with the A34 super track pack option of PS/PDB, Max cooling package and 4.10:1 Dana 60. Yes....the bakelite pistons were troublesome. I also use the DOT 5 Silicon brake fluid and have used it for 10+ years without any issues....I would recommend it.
BOB RENTON
Ding ding! Winner! I looked them up and this is exactly what they are. Thank you.
mrhemi
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I have had DOT 5 Silicon fluid in mine (Bendix) for nearly 40 years with no issues.
I'd like to hear the Pros and Cons of using Dot 5 in an automobile .
Interested to see what you guys are seeing. Other than it won't wreck the paint (which I totally get on an expensive car)
Interested to see what you guys are seeing. Other than it won't wreck the paint (which I totally get on an expensive car)
mrhemi
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I used it way back then exactly for that reason. Owning a Hemi car that I actually drove, I was concerned about spilling brake fluid when the master cylinder was removed for engine maintenance, spark plugs, valve lash etc. Over the years, I have seen it bad mouthed for long term use because of potential water egress stratifying and causing corrosion. I have never experienced this, however, my car has always been kept in a climate controlled environment.
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IMO.....
The lack of corrosion due to absorbed moisture due to the hydroscopic (affinity to pull moisture out of the air) nature of DOT 3 & 4 fluid. This absorbed moisture causes the primary piston seals to form a sludge/rust in the caliper body and pistons, especially in the rear wheel cylinders. The silicon fluid, DOT 5, is NON-HYDROSCOPIC. it has a slightly lower boiling point than DOT 3/4 fluids, but are you operating the braking system to that point?? Not likely.
The only con is the cost...DOT 5 fluid is approximately 3x-4x the cost, but weigh the cost vs overhauling calipers/wheel cylinders vs the incremental differences, including your labor to affect repairs. The other issue MAY be the fact DOT 5 fluid is NOT RECOMMENDED for anti-lock brake systems, but how many or your collector cars have anti-lock brake systems? Not a valid argument.... Just talking out loud.....
RJRENTON
Dot 3 is horrible stuff especially in the Northeast where it picks up moisture.
First thing I do on my cars is get rid of it.
First thing I do on my cars is get rid of it.
mrhemi
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All true with the caveat that the potential "moisture issue" is due to it being non-hydroscopic. In vehicles that sit for extended periods such as a museum piece, the atmospheric pressure changes allow condensation to collect and pool over time, causing corrosion in the low point pooled locations. The fact that is is non-hydroscopic can leave moisture in the system even when it is flushed with new fluid. As I indicated, I have had it in mine for nearly 40 years with no issues, but the car is driven fairly regularly and kept in a climate controlled setting.
ckessel
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Looks like the factory installed units on my 73 Duster.
69_Coronet
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I agree with what is said here with one minor correction. DOT 5 brake fluid has a higher dry boiling point (260 C) than DOT 3 (205 C) or DOT 4 (230 C). There is also a DOT 5.1 fluid that has the same glycol base as DOT 3 and 4, but has the same boiling point as DOT 5, which uses a silicone base.
One issue I have seen with using DOT 5 is that when filling the system, it is easy to get a bit of air in the fluid from it being captured during pouring. You should be careful when pouring to avoid splashing, which will cause air to be captured in the system. Don't shake the container before you use it.
One very nice feature with DOT 5 fluid is that, because it is not hygroscopic, you can store an opened (and reclosed) container for it for much longer than you can with DOT 3 or 4.
I have DOT 5 in my Coronet, and the brake pedal feels nice and firm to me. This is with a Dr Diff (Disc-O-Tech) disc brake conversion in front and completely refurbished drums in the rear. I replaced the master cylinder with one recommended by Dr Diff when I did the conversion, but I left the system as manual brakes. Cheers!
How does moisture get into a sealed system? I mean enough to pool? In a normal system, the hydroscopic nature of dot 3 and 4 can absorb moisture past seals and the air, but since dot 5 does not absorb moisture, how does it get into the system? Dot 3 draws it in.
69_Coronet
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A brake system is not completely sealed, there is a vent on the master cylinder reservoir, at least on many systems. A small amount of air will move into and out of the reservoir due to heating and cooling, and the small amount of moisture in that air can condense in the reservoir due to the temperature changes. Also, as you brake pads and/or shoes wear, more air will be drawn into the reservoir to replace the volume of brake fluid needed to compensate for the wear, and this air will have some moisture in it that can condense. In general, a system with DOT 5 fluid should not wind up with very much moisture at all, since the amount of air inside the reservoir is very small. Cheers!
Ok, master cylinders have rubber expansion seals inside their caps that allow atmospheric pressure to push them down into the reservoir to displace the fluid being drawn from the reservoir. This is the thing you have to wiggle back up into the cap when fluid is low and you replenish it, which shouldn't be done but most people do it anyway.
Moisture does get in around the seals, but usually because of the dot 3's propensity to attract and absorb moisture.
I get what you're saying tho, if moisture does get into a dot 5 system, it will just lay there, where in a dot 3 system it will be absorbed into the fluid. Good point, and I am for sure going to use Dot 5 in my belvedere. Thanks to all.
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