3.8 pedal box query

Technical advice Q&A

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Etype Maria
Posts: 2
Joined: Sun Dec 22, 2019 10:00 pm
Great Britain

#1 3.8 pedal box query

Post by Etype Maria » Mon Feb 24, 2020 8:43 pm

If a 3.8 pedal box has two rear master cylinders on it what is the outcome , or two front cylinders for that mater ,
My symptom is holding on of the front brake , no matter how much I adjust the adjustable push rod , which is going into the rear ( top ) master cylinder ?
Thanks in advance
Maria x

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abowie
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#2 Re: 3.8 pedal box query

Post by abowie » Mon Feb 24, 2020 8:57 pm

If what you are referring to is the different lengths of the internal piston on the original masters then the brakes should still work even without this. New masters contain pistons of the same length.

So I doubt that this is the cause of your front brakes sticking on. I would be looking at the calipers and the flexible hose, and making sure that the pedal box is assembled correctly and that nothing is jamming it.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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rfs1957
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#3 Re: 3.8 pedal box query

Post by rfs1957 » Tue Mar 03, 2020 4:07 pm

If you want to know more about the respective behaviours of the front and rear master-cylinders, this thread tried to work out what goes on in there.

viewtopic.php?f=4&t=4120&p=27776&hilit=SMOKE#p27776

It's worth reading just to explode some of the cod-science that has grown up around them.

In fact, please go and read it as I've just wasted half an hour restoring all the photo links.
Rory
3.8 OTS S1 Opalescent Silver Grey - built May 28th 1962

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