Morris Minor Forum

I have the Ford based kit, been running it for 20 years now, never had a problem.... No residual valves. If the system is properly bled and the rear shoes are properly adjusted the most pedal travel I get is half way down pressing as hard as I can and much harder than I would need to press when driving. These cars were never originally fitted with valves and I feel that fitting them is introducing a potential failure point, potential to leak at least. Get yourself a vacuum bleeder and some good quality flexible hoses, flush with new fluid and enjoy your brakes again.

Sorry Stewart, but this is just your opinion, but factually incorrect and thus misinformation. Yes, it can be done this way, but it's not correct.

I have been installing external residual valves for more than 20 years (so do all hot rod and resto-mod builders) and never had a failure point. Ask any brake specialist, hot rod or experienced custom car builder, and they will tell you the same. Yes, that's a possibility, but only with someone who should not be doing their own brake work/modifications. Brake work is not for the inexperienced shadetree mechanic. People can do whatever they please with theor cars, but they should be equipped with accurate information.

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Gerard

http://gerardsgarage.com/

well Gerard, I agree that people should be equipped with accurate information, but the fitting instructions supplied with the Ford kit makes no mention of extra valves. How many kits have been sold and fitted with no problems. You can continue to tell people they need to fit external residual valves because without them it's not correct. Your opinion, my opinion

It's not an opinion... it's engineering fact.

Here are just a few of many examples examples that support my "opinion". In addition, I have worked for over 25 years with a brake specialist and a mechanical engineer who have the same "opinion".

https://techtalk.mpbrakes.com/how-to-series/four-things-to-know-about-brake-valves

https://www.freeasestudyguides.com/residual-check-valve.html

http://www.mbmbrakeboosters.com/index.php?option=com_content&view=category&layout=blog&id=8&Itemid=16

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Gerard

http://gerardsgarage.com/

Why do you think that Willys and Morris fitted residual pressure valves please Stuart?

From Post #16
I have the Ford based kit, been running it for 20 years now, never had a problem.... No residual valves. If the system is properly bled and the rear shoes are properly adjusted the most pedal travel I get is half way down pressing as hard as I can and much harder than I would need to press when driving.

If losing 1/2 of the pedal travel is OK, then go for it. Technically there is still brake available in the last 1/2 of the stroke. Though residual valves may not be an absolute necessary, I'm with Gerard. Why give up 1/2 of the stroke when more is available by simply installing the check valves. I even added 2 psi residual valves on both circuits of my MGB after I converted the rear to disc. That made a world of difference in the pedal feel.

The potential for leaks is wholly dependent upon the workmanship of the installer, with or without the residual valves. If there is a concern for component failure then get the best product you can afford. Just keep in mind that there is a potential failure for every component in the system. If adding another component is of concern, then don't add the component.

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If it was good 60 years ago, does that mean it can't be improved?
Know the rules well so you can break them effectively. Dalai Lama

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https://www.mgexp.com/journal/Charles-Durning.2966/toc

Keep fitting your residual valves.... Because your "Brake specialist" and your "mechanical engineer" say anything else is not correct . I have converted more than one minor and fitted the kit as sold with no problems.... That of course is just my opinion.

That's all I did 4 years ago, stops great, pedal has less than 1/4" travel to start braking, haven't even had to top off fluid yet.

Charles, please will you explain to me
using short sharp words and short sharp sentences
why you think pressure retaining valves are a good idea.

Also, please will you explain to me
using the style I asked for above
why you think Stuart is "losing" 1/2 his pedal travel?

I'm American is not my language
hence, I ask for that style of writing

I think you guys are mixing your metaphors sort of speak. Designers installed residual valves in the master cylinder to cover all circumstances. Under some conditions as temperatures change and what not. The relaxed fluid pressure could drop below atmospheric which would be conducive to pull moisture into the system since the fluid of the day was hygroscopic. Since drum brakes have return springs, they took the easy route and maintained a bit more pressure. In a retrofit when bits or mixed and matched, the appropriate external residual valves perform the functions. Now you have a system that OEM designers could stand behind to cover all circumstances. However, that doesn't mean you will have a problem if you don't use them. You run a slight chance of pulling in moisture when the system isn't at positive pressure. Whether this positive pressure is maintained over a six month storage is questionable. Also bear in mind that the wheel cylinders have cup formers and internal springs which may help to keep the system stay sealed. I also must comment on the thoughts that the residual valves are reducing pedal travel. The travel required to develop 2 to 10 psi in next to nothing considering the operating pressures. Excess travel is a sign of excess fluid movement, so somewhere there is excessive pull back. Along those lines and may void all that I stated above, the residual valves probably allow "pumping up" the brakes. With the fluid being in-compressible, so without residual valves a stroke would pump fluid and the return stroke would bring it all back and everything would be the same as before. The residual valves will create a vacuum in the master cylinder when returned, allowing fluid from the reservoir to flow into the chamber for another firing. You can get away without residual valves, but it would be best to have them in one form or another.

A interesting and logical post, Jim. Thanks. Rob.

Looks like both sides are deeply entrenched and neither will be swayed. The pro residual folks are offering a solution to a problem that could arise and have experienced. The never residual folks are happy as is. So be it. Let's move on.

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If it was good 60 years ago, does that mean it can't be improved?
Know the rules well so you can break them effectively. Dalai Lama

Journal index
https://www.mgexp.com/journal/Charles-Durning.2966/toc