RansomEli

1929 135 Brake Repair

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Posted (edited)

Finally getting around to re-doing the brakes on my '29 135 sedan. New wheel cylinders (thanks to Jeff Hasslen), rebuilt master cylinder. Brake lines and hoses look OK, but I will probably get new hoses because they are at least 15 years old.

 

Removed the Master Cylinder head and barrel looks like crap. Am sending it out for rebuilding. 

 

The supply tank has a bunch of crud in it, too. Any suggestions on how to clean it out?

 

A couple of questions:

  1. After getting the master cylinder head and barrel rebuilt, it's supposed to be "indexed."  What exactly does that mean?
  2. The topic of DOT 3 or DOT 5 brake fluid has been extensively discussed in the AACA forums. Without going into the previous discussions, should I use DOT 3 or 5 in my Franklin?

 

I can't tell you how relaxing it's been to finally get underneath my '29 again. My Franklin mentor (long gone) had two '29s. He couldn't physically work on them anymore, so we had a deal -- he'd provide the knowledge and I'd provide the muscle. Working on my car brought back fond memories.

 

It also helps that my '29 had some good people working on it. Everything was nice and neat underneath. All bolts and nuts were tight, but not too tight. 

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Edited by RansomEli (see edit history)

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Posted (edited)

Send the entire master cylinder box to Apple Hydraulics. They will clean it all, sleeve and index the bore, and replace the lever shaft seal. All you have to do is mount the box back in.

 

The DOT 3- DOT 5 debate is just that. I could do a long post on the problems I've seen with DOT5 and someone else would pop on and say they never had problems. 

 

There's nothing wrong with DOT 3 if you pump some fresh fluid through the  system every few years.  BTW, no brake fluid is meant to be left in forever. 

 

Water gets into the DOT 5 systems, too. Franklin brake systems are not sealed like more modern systems. Every time you pump the brake pedal air and moisture moves into the reservoir.  I've seen where that moisture condenses, settles, and had collected in the low points of many DOT5 systems after I had to open them up. The moisture can't be kept out and it can't mix with DOT 5 fluid and be dealt with safely the way DOT3 & 4 are designed to handle moisture.  And as it collects, it can freeze in cold weather causing brake problems. That's why it's not used in modern cars.  But they never bother to tell you that. 

 

And the old sales pitch that the government uses DOT5 so that they don't need to change it is not true. The brake shop in Farmingdale LI that used to do my cylinder rebuilding had the USPS contract for doing the brake systems on post office vehicles. The owner of the shop said he loves that the USPS is using DOT 5 because as he put it, "It's putting my kids through college." 

 

Paul 

Edited by PFitz (see edit history)
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Whatever you do with Dot 3 v Dot 5 - DO NOT mix the two - that creates a ghastly gelatinous mess.

 

Roger

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I have been running Dot 4 in all the cars - it is less hydroscopic than Dot 3.   I hatted Dot 5 on the Franklin as there was allways a drip of it somewhere on a fitting (just added more, but ....).

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10 minutes ago, John_Mereness said:

I have been running Dot 4 in all the cars - it is less hydroscopic than Dot 3.   I hatted Dot 5 on the Franklin as there was allways a drip of it somewhere on a fitting (just added more, but ....).

Same problem I’m having. Next time it will be DOT 4. 

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Posted (edited)
59 minutes ago, stvaughn said:

Same problem I’m having. Next time it will be DOT 4. 

Every year I put maybe an inch of silicone fluid in the jar - car would throw you through the windshield stopping so never worried about that - but just hated all the drips hanging on the fittings. 

Edited by John_Mereness (see edit history)

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5 minutes ago, Brooklyn Beer said:

How can you tell if the fluid in the car is DOT 3  4  5  ? 

Pump some out into a clear glass jar then,

  *   pour some fresh Dot3/4, if reaction, you have dot 5 in there

   *  pour some fresh Dot 5, if reactin, you have dot 3/4 in there.

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29 minutes ago, Brooklyn Beer said:

How can you tell if the fluid in the car is DOT 3  4  5  ? 

All the DOT 5 I’ve used is purple although some brands are different. 

 

And yes DOT 3 & 4 are compatible. 

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One of the standards to meet DOT specs is  that the different categories of brake fluids have to all be compatible.  In talks with a Wagner brake systems engineer, some of the problems in past have been caused by,  there are only a few companies making DOT 5 fluid, contamination and compatibility problems were traced to  some companies that bought from one of those companies and then rebottled the DOT 5.

 

Paul  

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So suck out a little brake fluid and mix with DOT 3 and if it stays separated it is 5 correct ?  

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Posted (edited)

One of the recommended tests is to put some of the brake fluid in question, in a clean dry glass jar. Drip in some water, wait and watch what happens.

 

If the brake fluid is  Dot 3, 4, or 5.1 the drops of water will dissipate in the fluid as it should. At most, the brake fluid will start to turn a bit milky looking. However, those brake fluids are designed to safely handle water and not let it separate out as just water, which will boil at far lower temps than even water contaminated DOT 3 brake fluid does. Water in DOT 3. 4, 5.1 fluids is not a problem as long as it does not get to "gross contamination levels" the term a brake engineer told me about.  That's why it should be flushed with fresh fluid every few years if the car is drive in damp climates areas of the country.

 

With DOT 5, the water can not mix. Being heavier than DOT 5, the water will sink to the lowest point, such as the bottom of master and wheel cylinders and remain as just water that will boil at 212 F.  Or freeze  if it gets below 32F.  

 

And if you think Franklins don't get water in a DOT 5 system, think again. I've opened up many DOT 5 systems and EVERY ONE had what I call the DOT 5 foot print. Rust spots on the bottom of the master cylinder and wheel cylinders where water had settled and collected into a growing drop of water. Every time the brake pedal is pressed fluid  moves in and out of the vented master cylinder reservoir and so does air with moisture. That moisture can condense, collect into droplets, and sink to the lowest point, which is the master cylinder.  But that's not the only way water gets into a brake system.

 

Yes, DOT 5 does not attract water, but that doesn't stop the natural phenomena of "vapor pressure" - moisture moving from a high concentration area to a low moisture concentration area forcing moisture into the system.  The difference is DOT 3,4, and 5.1 are designed to work with that, DOT 5 can't.  I found that the worst rust spots in the DOT 5 systems are usually in those parts closest to the reservoir (master cylinder) and the two front wheel cylinders because of the brake hoses being so close to them. Lesser rust shows up in the left rear wheel cylinder, it being the furthest from the rear axle brake hose.  Wagner did tests and found that moisture - being one of the smallest molecules - can go right through the brake hose walls and the rubber in cover some the master cylinder reservoirs,  because of natural vapor pressure. Even with modern brake systems moisture can't be kept out 100%.  

 

Yes I know, there are owners who say they have not had problems with DOT 5 in their brake system for years. But, how many ever bother to open the entire system to  do a thorough inspection ?  I've had to rebuild too many DOT 5 systems to ever again be a believer that it's a "do it and forget it" brake fluid for Franklins, because when it first came out I was using it too.  My advice is, if your going to use DOT5 and you live in one of damper areas of our country, treat it like Dot 3 and flush new fluid through every few years. The tools to do it are simple, there's no need to jack up the car, it takes less than an hour with the help of someone to press the brake pedal, and a quart of new fluid is plenty to flush the entire system.

 

I know this will ruffle some feathers, but since having to redo so many DOT 5 systems I no longer recommend using DOT 5 to my customers. If they want to use it that is their prerogative, but I won't do the job.

 

 Paul

Edited by PFitz (see edit history)
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Paul,

 

What is your recommend way to clean out the hard lines if I decide to change back to DOT 3/4? 

 

Steve

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37 minutes ago, stvaughn said:

Paul,

 

What is your recommend way to clean out the hard lines if I decide to change back to DOT 3/4? 

 

Steve

 To flush any of the DOT brake fluids use alcohol.  Then blow the lines dry with clean compressed air.  By clean I mean from a compressor that has air line filters and water traps so that it is not blowing oil or water vapor into the brake lines.  

 

Or, if they are the original brake lines, be safe and replace them with new  high-strength copper lines and brass flair nuts from the Club's website. The old brass flair nuts have been known to suddenly crack from decades of outward pressure. Especially dangerous if they are turning pink-ish as the zinc leaches out and weakens the brass.

 

Paul

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Use denatured alcohol from the hardware or auto shop, household stuff contains water.

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Thanks Paul, all my hard lines are new cunifer. One would be very difficult to replace now that the car is assembled. Is it ok to use the alcohol on the flex lines?

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5 minutes ago, stvaughn said:

Thanks Paul, all my hard lines are new cunifer. One would be very difficult to replace now that the car is assembled. Is it ok to use the alcohol on the flex lines?

 Yes, not as easy as a bare chassis, but most of the Franklins I've replaced the lines on were assembled cars. To quote H.H.Franklin's office sign, "It can be done."  

 

The alcohol won't harm the brake hoses. Just make sure to dry it all out thoroughly after flushing until you see clean alcohol coming through.

 

Paul

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13 hours ago, PFitz said:

 Yes, not as easy as a bare chassis, but most of the Franklins I've replaced the lines on were assembled cars. To quote H.H.Franklin's office sign, "It can be done."  

 

The alcohol won't harm the brake hoses. Just make sure to dry it all out thoroughly after flushing until you see clean alcohol coming through.

 

Paul

 

I need to hang this motto in my shop. 

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Posted (edited)

I copied one that was over a customers office desk and placed it above my shop door.

 

"Why is it that some people never have time to do a job right the first time, but always find time to do it over ?"

 

Paul

Edited by PFitz (see edit history)

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Well that's better then the motto the  electricians on the school were are building have.

 

" We do it right all three times"

 

Enjoy trek. !   Remember me if you see a rear foot rest !

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Update: 

 

I sent the master cylinder to Brake & Equipment Warehouse in Minneapolis. Tom Rasmussen and Jeff Hasslen have used them many times and I decided to follow in their footsteps.

 

Received the unit back in about a week. Looks nice, although I won't know until I actually drive the car.

 

Have all new brake parts from Jeff Hasslen. Need to flush the brake lines (they look good so I won't replace them) and install parts.

 

Based upon your recommendations, I'll use DOT 4 brake fluid.

 

Thanks for the advice.  Will keep you posted on my progress. 

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I recommend that you replace the lines, too. That's the part of the system that can and has, suddenly failed leading to brake loss when one of the old brass flair nuts cracks from decades of outward tension of the tapered seat.  It's not uncommon to find one or more of the flair nuts already cracked and waiting to let go. If any fittings are turning pink-ish they are wreakened from zinc leaching out of the brass and can break even more easily.

 

That's why the Club is selling new high-strength copper/nickel brake line, and the proper SAE spec flair nuts.

 

Paul

Edited by PFitz (see edit history)

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