1961 Front Wheel Cylinder Orientation

[Mike B.]

I started rebuilding the front wheel cylinders as I found one weeping. The kits are 1-3/16" diameter. I rebuilt the LF no problem but when I moved to the RF, I found it to be 1-1/8" so it is likely an aftermarket unit. Regardless, I want to balance the hydraulic pressure by having the same bore size so I started looking to find a match for the original cylinder.

The original mounted in the LF has a casting number of 5459528 which lists as the right front (it's never easy). The way they are presently configured, the brake hose nipple points to the rear on both sides. If I were to install them according to the listing, the orientation would be with the nipple facing the front which does not seem right since the hose is attached to the brake line from the rear, and there does not seem to be much extra hose to allow a gentle sweep to the front of the backing plate area. Perhaps those hoses are wrong too. The AIM is not particularly clear but it looks like the nipples face to the front.

Can someone please provide a definitive answer to the correct orientation? Also I would appreciate a modern source and part number and/or cross such as another GM car with the same cylinders as I may just replace both, most likely with 1-1/8" replacements as they seem more likely to be available. NAPA does not list a replacement front cylinder for 1961 regardless of the diameter.

Thank you,
Mike

[Chris H.]

Re: 1961 Front Wheel Cylinder Orientation

Take a look at photos.

user name and password is chenige

http://www.photodex.com/sharing/viewalbum.html?alb=105064

[Bernard M.]

Re: 1961 Front Wheel Cylinder Orientation

Mike, Castings 527 (L) and 528 (R) would be original for standard brakes. They are 1-3/16" bore. Heavy duty front brakes for 61/62 used 1-1/8" bore cylinders. My '53-'72 Corvette Parts & Accessories Catalog lists the HD cylinders as the same 1-1/8" bore 821(L)/822(R) casting units used on '53-'59 Corvettes. These aren't easy to come by either but my 1950-1965 GM Interchange manual lists P/Ns 5455478 & 9 as replacements that are also used on 51-54 Chev, 51-52 Chev 1/2T Pickup except 4x4, 53-59 1/2T P/U, 64-65 1/2T P/U 4x4, 60-63 3/4T P/U fwd or 4x4 and 64-65 3/4T 4x4. There may be later year applications as well, but my interchange book only goes to 65. These references are both pretty old so I'd recommend you take one with you when you go shopping for comparison purposes.

[Mike B.]

Re: 1961 Front Wheel Cylinder Orientation

Thank you gentlemen. That is exactly the information I sought. And according to Chris's photos, the brake nipple would face the rear of the car (same orientation as the steering arm) therefore mine are installed correctly. But that begs the question: What is the right-hand wheel cylinder doing on the left side of my car?

I will soon forget about it driving down the road...

[Roy B.]

Re: 1961 Front Wheel Cylinder Orientation

This can be a easy thing to remember (any part or casting number ending in 2-4-6-8-0 is a part that goes on the right side of the Corvette,
1-3-5-7-9 goes to the left side of the Corvette.
If a part is NOT USED on the right or left side ,the last number don't matter.A simple thing to remember!!!

[Mike E.]

Re: 1961 Front Wheel Cylinder Orientation

Roy,
You missed his point. He knows that evens go on the right, and odds on the left. But his 528 (even) wheel cylinder is on the left, and is configured and oriented correctly. That's why he's asking the question.

[Michael H.]

Re: 1961 Front Wheel Cylinder Orientation

Mike,

I believe the current configuration of your front wheel cyl's would be correct with the odd casting number on the right. About a year ago, this topic came up here on the discussion board regarding some other part and I explained that parts ending in even numbers were almost always used on the right side of the vehicle. It's the "almost always" wording that applies here.

It has always been the intent of GM to use the even number on the right and that's exactly what was done when these wheel cyl's were designed. However, the ORIGINAL application/installation for these cyl's was exactly opposite of the installation on Corvette. The original design was for pass car and truck, and the even number WAS on the right.

If you look in an old passenger car and Corvette parts book, the listing clearly indicates that a 5455479 cyl was used on the LEFT front of all 51-54 pass and 53-59 D-D truck and Corvette, but was also used on the RIGHT front of 60-62 Corvette w/HD brakes and susp.

The listing goes on to explain that the 1 1/8" dia cyl was used for 60-62 with HD brakes/suspension and a 1 3/16" dia cyl was used for standard brakes.

In a may 1963 printing of the parts book, it lists you're 5459528 casting number as the correct RIGHT front cyl for 60-62 WITHOUT HD brakes/susp. That means that the standard cyl's with even part numbers for the right were unique to Corvette and not used on pass car.

So, cyl's for standard brakes used RH/even numbers. HD brakes used RH/odd numbers.

If you're confused, you're not alone. This has been a very confusing issue for a lot of folks for many years. Hope this helps.

[Roy B.]

Re: 1961 Front Wheel Cylinder Orientation

OK ! But most even numbers are for the right side of a Corvette unless it can be used on ether side

[Mike B.]

Re: 1961 Front Wheel Cylinder Orientation

Thanks for the explanation. Logic prevailed over part number. It made sense as it was installed on the car but the part numbers threw me a curve. Most likely passenger car brake hoses fed from the front, Corvettes from the rear which demanded that the mirror-image wheel cylinders be flipped. My parts book which preceeds the 1963 reprint does not make a clear distinction.

Thanks again to all. One certainly learns something everyday.

Regards,
Mike

[Chris H.]

Re: 1961 Front Wheel Cylinder Orientation

The C1 front crossmember/suspension was taken with litle change from the 52 chevy. This vehicle has the same hose orientaion as the vette so that is not where the odd number on the right side started.

Looking in a "chev of the 40's" restoration parts catolog I see that a part number 5300869 for both fronts on a '36-FD and then 5300866 for the fronts on a '36-FC. So they used the same part on both sides of these vehicles.

For 36-48 they list 5300953 as front right for all models except front left on '37-38 GB, HB. 5300954 was used for the opposite of the above.

For '49-'50 they lists 5450988 for right and 5300989 for left.

For '51-'54 5455478 for left and 5455479 for right.

I guess I see no answer in the above to the question of why. In looking at the '50-65 interchange manual the '53-'59 and '60-'62 HD Corvette wheel cylinders were also used in trucks. Perhaps they were used there in the typical even/ right orientation?

[Michael H.]

1963 parts Book Scan #1

Chris,

Here's the first scan of Gr. 4.665 in a 63 printing of the parts book. Note the app for the 5455478. It usage is, among other things, a 53-59 Corvette in the RIGHT front position, and a 60-62 Corvette w/ HD Brakes, for the LEFT front. The part number is an even number which would usually indicate a part for the right side of the car. Obviously, this cyl was designed before Corvettes were on the planet as one of it's app's is a 51-54 pass, right front. The odd casting number makes it even more confusing.

[Michael H.]

1963 Parts Book Scan #2

Note the odd part number, 5459519, for the right front of a 60-62 with std brakes.

[Roy B.]

Re: 1963 Parts Book Scan #2

On all the number discussion , don't later "part" numbers supercede old "part" number which in turn may not match a "casting" number? I see this many times on E-bay with seller saying the " BOOK part" number said it would fit 53 to 76 Corvette!

[Michael H.]

Re: 1963 Parts Book Scan #2

Yes, that's exactly right Roy. Many times a part number will change but the part will retain the original casting number from the original application.

Wheel cyl's are some of the most confusing parts to look up, especially for the rear of a 63-64 Corvette. The parts books have been incorrect on the application for the rear cyl's for decades. It shows the 63 pass car as having the same cyl as Corvette when, in reality, the Corvette application was reversed. The right rear 63 pass cyl was used on the left rear of a 63 Corvette.