Drum Brake Wheel Cylinder Evaluation
- Dennis Vogel
- 356 Fan
- Posts: 505
- Joined: Sat Oct 25, 2008 6:10 pm
- Location: Santa Rosa, CA
- Contact:
Drum Brake Wheel Cylinder Evaluation
How do you evaluate if a drum brake wheel cylinder is good enough to rebuild and reuse? The factory workshop manual basically says tear it apart, inspect for wear and damage, reassemble.
It seems like master cylinder rebuild kits are readily available from the usual vendors, but not so much for the wheel cylinders. They only seem to want to sell new replacement cylinders. The only exception I've found in the US is Parksklassic.
If I rebuild them, is there anyway to test if I've been successful short of installing them on the car and testing the entire braking system?
The car has been sitting for over 20 years, so I'm planning to replace all the rubber and springs. Anything else I can safely salvage I will for originality and personal satisfaction.
It seems like master cylinder rebuild kits are readily available from the usual vendors, but not so much for the wheel cylinders. They only seem to want to sell new replacement cylinders. The only exception I've found in the US is Parksklassic.
If I rebuild them, is there anyway to test if I've been successful short of installing them on the car and testing the entire braking system?
The car has been sitting for over 20 years, so I'm planning to replace all the rubber and springs. Anything else I can safely salvage I will for originality and personal satisfaction.
1960 356 S90 Sunroof Coupe
1970 914-6
2014 Carrera S
1970 914-6
2014 Carrera S
- Bruce Smith
- 356 Fan
- Posts: 1625
- Joined: Sun Jun 19, 2011 9:47 am
- Location: Rochester, NY
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
Dennis - Here's an article I wrote for the magazine last year. I think it has your answers. - Bruce
http://www.sparkingplugs.com/resources/ ... 282$29.pdf
http://www.sparkingplugs.com/3.html
http://www.sparkingplugs.com/resources/ ... 282$29.pdf
http://www.sparkingplugs.com/3.html
Bruce Smith
- Don Gale
- 356 Fan
- Posts: 1183
- Joined: Wed Jul 26, 2017 6:27 pm
- Tag: Black A's Matter
- Location: Albuquerque
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
The 356 repair kit with new cups and boots is 644.351.912.01 and Stoddards lists them. The VW kit also has new pistons, p/n 113.698.273 available on ebay. Excellent write-up Bruce. The Porsche service manual doesn't list a tolerance for the piston to cylinder clearance but Elfrink does, 0.002-.004" and to replace them if honing pits takes them beyond that. The fronts and rears are the same. $225 to $250 for a set of 6 new complete cyls from numerous vendors.
1958 356A 1600 Super Sunroof Coupe
former 1966 Euro 912 Sunroof
former 1978 Intermeccanica Speedster w/'68 912
Member Since 1983, #4039
"Nostalgia isn't what it used to be"
former 1966 Euro 912 Sunroof
former 1978 Intermeccanica Speedster w/'68 912
Member Since 1983, #4039
"Nostalgia isn't what it used to be"
- Jim Liberty
- 356 Registry Member
- Posts: 4320
- Joined: Tue May 06, 2008 3:47 pm
- Tag: Jim
- Location: Orange Co., CA
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
I go for the ATEs on all my restorations. Only two things count 1.) steering 2.) stopping. .............Jim.
Jim Liberty
- Wes Bender
- 356 Fan
- Posts: 4941
- Joined: Wed Aug 27, 2008 10:54 am
- Location: Somewhere in the Gadsden Purchase, USA
Re: Drum Brake Wheel Cylinder Evaluation
When you put the new ones/refurbished ones back on, pay particular attention to the direction the star wheels face. Installing one or more backwards will give you little to no braking on that particular wheel.
Some days it's just not worth chewing through the restraints.....
- Jim Liberty
- 356 Registry Member
- Posts: 4320
- Joined: Tue May 06, 2008 3:47 pm
- Tag: Jim
- Location: Orange Co., CA
- Contact:
- Harlan Halsey
- 356 Fan
- Posts: 2374
- Joined: Fri Mar 02, 2012 2:05 pm
- Location: No Cal SF Peninsula
Re: Drum Brake Wheel Cylinder Evaluation
It is cheap and therefore fashionable to replace brake cylinders these days. But it wasn't always so. Brake cylinders corrode much more than they wear, and I noted that the corrosion pitting was usually at the bottom and at the edge of the cup stop. The rest of the cylinder was usually OK. A cylinder could often be saved by shortening the piston so that the cup travel didn't include the pit. Alternativly, White Post would sleeve the castings in brass cheaper than new cylinders. Sometimes it is better to understand the problem rather than throwing new parts at it.
I solved the corrosion problem years ago by going to silicone brake fluid. At least I think I did: In 1974 I completely renewed the brake system of my Convertible D. I have never since had a leak, nor have I added any brake fluid. The car has covered may be 30,000 miles since then, but I have never had occasion to disassemble a cylinder and asses its condition.
I solved the corrosion problem years ago by going to silicone brake fluid. At least I think I did: In 1974 I completely renewed the brake system of my Convertible D. I have never since had a leak, nor have I added any brake fluid. The car has covered may be 30,000 miles since then, but I have never had occasion to disassemble a cylinder and asses its condition.
- Joris Koning
- 356 Fan
- Posts: 2518
- Joined: Thu Mar 27, 2008 12:38 pm
- Location: Netherlands
Re: Drum Brake Wheel Cylinder Evaluation
I have hears some rumor about the non ATE branded new cylinders sometimes having issues. Is this correct?
'56 Coupe
'57 Coupe
'59 Cab
'60 Coupe
'57 Coupe
'59 Cab
'60 Coupe
- Dennis Vogel
- 356 Fan
- Posts: 505
- Joined: Sat Oct 25, 2008 6:10 pm
- Location: Santa Rosa, CA
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
Thanks so much Bruce. That is exactly what I was looking for. I searched through the Registry Technical Library, but didn't see it.Bruce Smith wrote: ↑Sat Nov 26, 2022 1:36 pm Dennis - Here's an article I wrote for the magazine last year. I think it has your answers. - Bruce
http://www.sparkingplugs.com/resources/ ... 282$29.pdf
http://www.sparkingplugs.com/3.html
1960 356 S90 Sunroof Coupe
1970 914-6
2014 Carrera S
1970 914-6
2014 Carrera S
- Martin Benade
- 356 Fan
- Posts: 12390
- Joined: Wed Nov 23, 2011 10:52 am
- Location: Cleveland, Ohio
Re: Drum Brake Wheel Cylinder Evaluation
I’ve had a set of the cheaper wheel cylinders for about 11 years with no problems.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna
62 Cabriolet
56 VW
02 IS 300
04 Sienna
- Jim Liberty
- 356 Registry Member
- Posts: 4320
- Joined: Tue May 06, 2008 3:47 pm
- Tag: Jim
- Location: Orange Co., CA
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
I have had problems with the cheap wheel cylinders also. When they are faulty "Out of the box" I'm finished. Harlan, I switched to silicone fluid decades ago. Never had a problem. At first I feared dripping fluid on my paint, being the klutz I am. ..................Jim.
PS. Please tell everyone to look at BaT. My Glaser is on it now. "Baby needs new shoes".
PS. Please tell everyone to look at BaT. My Glaser is on it now. "Baby needs new shoes".
Jim Liberty
- Dennis Vogel
- 356 Fan
- Posts: 505
- Joined: Sat Oct 25, 2008 6:10 pm
- Location: Santa Rosa, CA
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
I can't be sure that they were original, but the rears are toast either way. One had the zirk fitting snap off. Then my removal tool snapped off inside of it. For the other side, the cylinder has a sizable crack in the lip. Hopefully I'll have better luck with the front.
1960 356 S90 Sunroof Coupe
1970 914-6
2014 Carrera S
1970 914-6
2014 Carrera S
- Wes Bender
- 356 Fan
- Posts: 4941
- Joined: Wed Aug 27, 2008 10:54 am
- Location: Somewhere in the Gadsden Purchase, USA
Re: Drum Brake Wheel Cylinder Evaluation
These's a limit as to how far gone they can be before you try to bring them back. From the looks of those, buy new all the way around. Jim Liberty has it right. You can't take chances with brakes or steering.
Some days it's just not worth chewing through the restraints.....
- Brian R Adams
- 356 Fan
- Posts: 3345
- Joined: Thu Mar 27, 2008 1:34 pm
- Location: N. Nevada
Re: Drum Brake Wheel Cylinder Evaluation
>> Only two things count 1.) steering 2.) stopping. ..... Jim
And for me, not necessarily in that order.
-
And for me, not necessarily in that order.
-
Welcome to the era of policy-based evidence-making.
Difficile est saturam non scribere (Juvenal)
Difficile est saturam non scribere (Juvenal)
- Al Zim
- 356 Fan
- Posts: 4377
- Joined: Thu Mar 27, 2008 12:37 pm
- Location: FT.WORTH/DALLAS TEXAS
- Contact:
Re: Drum Brake Wheel Cylinder Evaluation
Throw all your brake stuff away!!!!!! Including all the metal and rubber lines. Also replace the master cylinder with a dual stage master cylinder which were mandatory on all cars/trucks manufactured after 1967. Pay someone to help you on the installation. ZIMZ NEVER REBUILDS MASTERCYLINDERS!!! Zim
www.allzim.com
356 Parts and Services
www.facebook.com/ZimsAuto/
www.instagram.com/zims_autotechnik/
356 Parts and Services
www.facebook.com/ZimsAuto/
www.instagram.com/zims_autotechnik/