Early Lockheed Master Cylinder

[W MacDonald]

I would really appreciate some help from someone familiar with the very early Lockheed Hydraulic brake systems - in this case on a 1925 Chrysler Six, but used on others. To replace the incorrect setup on my car, I found most of the correct pieces in a box at Hershey but I am not certain that I got everything I need. Photos are attached - the cylinder is 1 5/8" bore with the Chrysler part number 54038 cast in. For the experts out there, here are my questions:

1. Is there anything missing from this set of parts?

2. The outlet fitting has an extension that sticks into the cylinder almost 7/8". The port is offset toward the bottom of the cylinder. This arrangement does not allow the use of a conventional discharge/return valve which normally clips to the end of the piston return spring and seats against a step in the bore. Is there any purpose for this extension other than a piston travel stop, and is there supposed to be some kind of valve?

3. I assume that there is supposed to be a piston return spring. The offset port bends a conventional spring a little, but seems that it would work. Is this correct?

4. What belongs in the 0.195" wide X 0.121" deep groove in the piston? The cup bolts to the back of the piston. The parts book (no illustrations) lists a "master cylinder piston washer felt, p/n 52541". Would it make sense that a square cross-section felt wiper belongs in this groove?

5. The wheel cylinders for the same car have a felt washer sandwiched between two brass washers to wipe the piston rods as they move in and out and keep dirt out of the cylinder. Is this master cylinder supposed to have a similar arrangement, or is the rubber accordion boot to serve this purpose?

6. Speaking of the boot, this cylinder requires a long boot for it's diameter - 1 1/2" on the big end, 5/8" shaft on the other end and about 4 1/4" relaxed length. Any suggestions for finding a suitable replacement?

Thanks for your help.

Wayne MacDonald

[HarryJ]

W......I will attempt to address your issue. This may be more confusion for you. I am presently in the process of restoring a '28 series "72" Chrysler (see restorations blog). From what I can see you have a B-70 series Chrysler, or the first series built. The brake cylinder you show in many ways looks similiar to the unit that fits my "72". According to the parts book I have, the master cylinders for the B-70 and the 72 are the same; however, I do find a reference to a series 70 part # 54508 installed on cars after serial number WD-506-L. I am including some pics of my cylinders for your review. According to what I know there is no piston return spring for the master cylinder and the piston cup is attached to the piston. Mine shows a small nub on the back of the cup that pops into a hole in the piston rather than bolting on as your parts indicate. My parts list shows a piston stop which looks like a large flat spring in the bottom of the cylinder; which may be the successor to your fitting extension. Note, does your cylinder have three studs it fits on? I hope I have added confusion to the question.

Edited December 31, 2010 by Harry J. (see edit history)

[W MacDonald]

Harry J.: Thanks for the response. The earlier cars, mine included, has the master cylinder pointing to the rear of the car and mounts via 4 bolts to the back left side of the transmission. Some additional information that won't help you or me but may be of some use to another reader is that there is at least one interim master cylinder between mine and yours. A photo is attached. This one looks like yours and is 1 1/2" bore, but points to the rear of the car and has a 4 bolt mount. This is the only piece I have from this cylinder (p/n 54509 cast in) Any chance you could post a photo of all the internal parts from your cylinder as I expect they should interchange with this one?

How do you suppose your master cylinder is to work without a return spring? There isn't much holding the cup to the piston, and the system would have to rely on the return springs at the wheel cylinders to return the master cylinder to neutral. At least on my cylinder the brake pedal won't pull the piston back, since the push rod is in two telescoping pieces - it can push but not pull.

Anyone else out there familiar with the earliest versions of the Lockheed master cylinder?

Thanks.

[HarryJ]

Wayne,,,,thanks for bringing this up! You have got me thinking about my brake system. From what I had figured to date, I thought this would be a no brainer! My master cylinder mounts on the engine block on the fly wheel housing with the open end to the rear of the car and not on the transmission. The wheel cylinder return springs must push fluid back to the master cylinder to return the piston to start/nuetral; as my car also has a sliding/telescoping push rod. , so the pedal cannot pull it back. Here are some pics of my assembly less the piston stop.

[HarryJ]

Wayne, here is a picture of my master cylinder from a series "72" owners manual. Note No. 3 (piston stop) and the nub on the cup that holds it in the piston. By the way, does your car have a brake light switch?

Edited January 1, 2011 by Harry J. (see edit history)

[HarryJ]

Wayne..........I just noticed the return question (at least for my car) is answered in the last paragraph above the diagram of the master cylinder in my last post. I checked the dust boot on the parts car I have, it is a leather boot, not rubber. Another point is, I read an ad some years ago (WPC News?) from someone who had reproduced the thick rubber hoses that go from the frame to the wheels. Do you or anyone else know who this was or where to find repros?

I also remember reading an article saying Chrysler had to totaly re-engineer the Lockheed brake system after they bought it as it would not function properly as first designed.

[W MacDonald]

Harry - My car has a brake light, but the switch is connected to the brake pedal, and does not sense pressure in the brake hydraulic system.

As for the flex hoses, you can get them from Jay Astheimer, 1092 Constitution Ave, Pen Argyl, PA 18072 Tel (610) 863-6955. These are made from commercial hydraulic hose with the end fittings modified to use the copper washer face seal. The end fittings are crimped on like any modern hydraulic hose, but these aren't easily visible on the car. The hose diameter is just about the same as the originals. Jay advertises in Hemmings and WPC News and probably has hoses in stock. I also saw a set of hoses that Branson Cheek made which look even more authentic, as he replicated the original end fittings. Branson has a machine shop at 1742 WOW Road, Asheboro, NC 27203 Tel: (336) 824-4641. Hoses would likely be a special order item from him. I got a set from Jay, and they fit the banjo fittings as they should - you will need to get your own copper washers.

Others advertise brake hoses that fit, but it seems they are made from the modern small diameter hose that just doesn't look right on early cars.

Speaking of copper washers, you will need three different sizes assuming that your banjo bolts are not drilled. Mine aren't, and this requires an odd shaped washer that fits over the 3/8" dia banjo bolt, but has spaces around the ID to let fluid pass. I have not been able to find a modern equivalent to this washer (which I think may be p/n 51496) or even washers with the correct ID and OD that would allow me to machine them to suit. Have you had any luck?

[HarryJ]

Wayne.........Thanx for the hose references. As to the copper washers and banjo bolts, would you publish some pictures of these items?

[W MacDonald]

Here's a photo showing the relative placement of the copper crush washers at each banjo fitting. The rear wheel cylinder parts are shown, although there is a similar arrangement at each end of all four brake hoses. Also shown are new washers available from NAPA that should work as replacements for p/n 51396 and 51463. The original brake hoses had a copper flanged sleeve pressed into the end of the fitting. As replacement hoses do not come with this piece, you will need to use a copper washer to seal the hose end to the banjo fitting. NAPA 26442 part should work here also, although you will have to reduce its outside diameter a little.

The big problem is the middle washer, which is designed to let fluid pass on its ID, since the banjo bolts aren't drilled. Drilled bolts must have been invented not long after 1925. Anyway, I have not been able to find either this type of washer or one with correct ID and OD that would allow machining the fluid passages. I may have to resort to annealing and reusing the old washers, although I'd hate to do that after all the work of making sure every other piece in the braking system is as-new.

Also, it would be great if you could post a pattern for the leather master cylinder boot.

Thanks.

[HarryJ]

Wayne, you should be able to use the original copper washers without heat treating them. A snug tight fit should make them seal properly. As to the leather boot , give me some time as I am using the parts car as a pattern and I will need to dismantle the assembly and clean it to obtain a pattern.

[Guest mick.wilson]

I have this problem times 10, I a re-building a 1944 Quick-way crane, it has 10 Wagner Lockheed cylinder that run the clutches on the crane, all need replacing and your photos look just like my ones, I need to have my cylinders re-bored but finding a replacement piston is turning into a nightmare. Are there cylinders,rubbers and pistons available in the USA as I can’t find any reference tothe part number “FD-384” in the UK

Regards

Mick

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Edited September 13, 2012 by mick.wilson (see edit history)

[W MacDonald]

Mick: What I ended up doing with my cylinder was the following: I had the cylinder bored and sleeved to standard size with brass by White Post Restorations in Virginia. For the cup, I purchased a standard wheel cylinder cup (available at any auto parts store, NAPA in this case) and punched a hole in the center for the attaching bolt. The felt wiper that goes in the groove in the piston I made, and I stitched up a leather boot for over the end of the cylinder. That took care of all the new parts required. Bleeding the system is somewhat different than a conventional system. Since the reservoir is located on the firewall well above the master cylinder and without a check valve anywhere in the system, it's a simple matter to just open the wheel cylinder bleeders one at a time and let the weight of the brake fluid push most of the air out of the lines. However, when you start pressing on the brake pedal to add pressure to force the last bit of air to the wheel cylinders you will find that the master cylinder does not return to the fully extended position since there is no internal spring. So you have to open the valve to the reservoir then physically pull the piston back out of the master cylinder to add fluid to the system, then close the valve and push the pedal again. Because of this, the piston cup has to be attached to the piston - mine is bolted, later ones seem to have a projection on the back that snaps into a recess in the piston. It took quite a few tries to fully bleed the system, but it's worth the effort. The braking system on my 1925 Chrysler works really well and makes the car a lot more fun to drive than a car with lesser brakes (like my 1923 Model T Ford or 1925 Dodge Brothers for example)