Brake bleeder screw size?

steve meltzer · 08-11-2019, 05:20 PM

Before I bleed the brakes again on my '74 Carrera, does anyone know the thread size of the bleeder screws? I'd like to have them in advance of the project in case I have any trouble with the existing ones. thanx steve

steve meltzer · 05:23 PM

my thanx to anyone who can help. steve

RWebb · RWebb's Garage

7 or 8 mm usually

steve meltzer · 08-11-2019, 05:47 PM

thanx. so much. steve

Bill Douglas · 08-11-2019, 07:56 PM

Steve I've just put speed bleeders on the SC. It makes bleeding the brakes soooo much easier.

pmax · pmax's Garage

Same here, speed bleeders, 1/4 turn, 10 pumps per caliper and you are done, 8mm is the size.

steve meltzer · 08-11-2019, 08:34 PM

thanx so much. when i was actively racing in PCA, i used those and they were great, but now, i only need to bleed the brakes every few years, so not worth the (moderate) expense. thanx. so they are 8M?? (that's what I want to know) thanx. s

Bill Douglas · 08-11-2019, 08:42 PM

On the SC the wrench size for the original bleeders was 8mm and the back 7mm.

steve meltzer · 08-12-2019, 05:37 AM

unfortunately, when you buy these they want the thread and diameter e.g. M8X1.00 or M8X1.25. That's what i need. thanx again. s

Bill Douglas · 08-12-2019, 11:17 AM

Sorry, the front is M8x1.25 and it had the designation of LL which may be long length to make it easier to get at. The back is M7x1.0 or just plain M7x1.

juanbenae · juanbenae's Garage

im not sure, but if you have the aluminum S caliper up front they may be different than the M's on the later SC/Carrera set ups. check the catalog here, or who ever you order them from for that specific car and what fronts it's equipped with.

I second the speed bleeder suggestion. ive got a vac bleeder that I never use due to the ease of the SB's. plus, if you have no motive bleeder or the like they can save you from a fight with the wife when you ask her to be the pedal person. you'd think pump, pump, pump,,,, hold would be simple, but well,,, you know.

steve meltzer · 08-12-2019, 12:04 PM

that's great and just what i needed! thanx. steve

SoCalSK8r · 08-14-2019, 07:30 PM

Just bled the brakes today, I had speed bleeders installed from the last time I changed out the brake lines. The speed bleeders are awesome, they make it an easy one man job.

Sent from my iPhone using Tapatalk

djpateman · 08-15-2019, 02:32 PM

Most cast iron calipers use 7mm by 1.00 pitch
Most alloy calipers use 10mm by 1.00 pitch (same as the brake line fittings)
If some calipers require 8mm I would like to know which ones.

steve meltzer · 08-15-2019, 06:57 PM

thanx again for the all of the info. clearly i'm gonna have to take out one or more screws and get the correct sizes. thanx. steve

steve meltzer · 09-09-2019, 02:19 PM

OK, it's been awhile since I followed up, but I replaced all of the bleeder screws on the '74 Carrera. One bleeder was sort of difficult to remove, but one was so difficult it took many applications (like a couple of applications every day of the week) of PB Blaster, Kroil, WD-40 and my MAP torch to remove it! I bought the replacements at O'Reilly. The fronts are as previously noted, M10 X 1.00 (and use a 10 mm wrench). The O'Reilly pack of 5 (in case you screw up, I guess) is Best Brake part #9409 and the rears are M7X1.00 (using a 7mm wrench) and Brake Best #9411.

I've bled the brakes on many cars, but never were the screws this tough. From now on I'll always loosen the screw, before starting the bleed, using a socket, (6 points trump 12 every time) and be patient. I think that on the tough ones a breaker bar is better than a ratchet. Gotta be patient.

steve

HarryD · 09-09-2019, 02:27 PM

Interesting to know. Wonder if the brake calipers were replaced ("upgraded").

Be careful with using force on them. They are not made of the strongest metal.

All 4 of my bleeders are identical.

steve meltzer · 09-09-2019, 02:57 PM

Harry, yep the bleed screw on the RF was nearly rounded off. So, I took a deep breath, pounded a 3/8 socket on to it and soaked, sprayed, heated, worked it back and forth (or tried to) and prayed. It still took a lot of force, but I got it off.s

djpateman · 09-13-2019, 10:06 AM

Quote:

Originally Posted by HarryD

All 4 of my bleeders are identical.

That depends on the car and the brakes that came with it. If the car has the normal brakes, then the calipers are generally cast iron with the 7mm bleeders. On the other hand if the car came with the aluminum S calipers or later multi-piston aluminum calipers and they have the external cross-over lines, then the bleeders are 10mm. A 1974 Carrera should have the S calipers.

steve meltzer · 09-13-2019, 12:52 PM

that comports perfectly with my '74 Carrera set up. thanx again. steve