7" to 8" brakes on front

Post by **sirrom** » Sun Mar 15, 2009 7:23 am

I have a '62 4dr which has 7" drums up front. I have an 8" backplate, drums, and shoes. Thinking of upgrading to 8" as the swept area of front brakes increases significantly.
Are the 8" front wheel brake cylinders the same as 7"

Post by **aupickup** » Sun Mar 15, 2009 7:31 am

yes i think they are

it is only the early mm that was different

Post by **kennatt** » Sun Mar 15, 2009 8:39 am

yes same,just done mine,vast improvement over7".

Post by **bmcecosse** » Sun Mar 15, 2009 9:58 am

Will indeed be a 'vast' improvement! If re-using the old cylinders - do at least clean them and put new seals inside!

Post by **sirrom** » Tue Mar 31, 2009 8:36 am

Another question can anybody help - is the front brake hose on a 7" drum the same length as the hose on an 8" drum

Post by **aupickup** » Tue Mar 31, 2009 8:52 am

yes i think they are the same length

Post by **sirrom** » Tue Mar 31, 2009 9:08 am

Changing from 7" to 8" and have just fitted to left side and went to fit brake hose and it seems to be very tight on the hose on full left lock. Just wondered if the 8" drums has a longer flexi hose. If someone has 8" can they measure the actual length of the hose excluding the fittings on the either end. The overall length of the 7" appears to be 300mm

Post by **aupickup** » Tue Mar 31, 2009 9:12 am

the only ones listed seperately on esm spares is 48 - 53

Post by **rayofleamington** » Tue Mar 31, 2009 10:54 am

You also need different brake shoe adjusters! I only learnt this the hard way when I mixed up some parts.
Differences are:

backplate
Drum
Adjusters
shoes
Flexi (is it really different?)
brake pipe between cylinders (longer on the 8")

The brake pipe between cylinders shouldn't be an issue really as it's unlilkely you can re-use old ones and most likely a new one will be long enough to do either version (or you make your own)

Post by **bmcecosse** » Tue Mar 31, 2009 2:11 pm

The wheel cylinder on the 8" brakes should only move about 1/2" from it's original position - so I would expect the hoses to be the same. Are you sure it's not 'twisted' and this is shortening it ?

Post by **sirrom** » Tue Mar 31, 2009 5:41 pm

When I got the 8" set it had drums, pipe connector between wheel cylinders,backing plate, wheel cylinders (seized),and adjusters. I have put new cylinders in and got new brake hoses.
To ensure that I have got the 8" adjusters can you tell me what the differences are to 7". I will compare as well but that will tell me what look for if they very a like

- thanks

Post by **aupickup** » Tue Mar 31, 2009 6:07 pm

the 8 inch adjuster has a bigger screw head

Post by **sirrom** » Wed Apr 01, 2009 5:51 am

Had a good look at them today and can see differences and yes screw head bigger and bigger at the rear (opposite to screw head).
Took some pics today at the 7" is on the left and 8"on right in pictures<br>

<br>

Post by **aupickup** » Wed Apr 01, 2009 9:38 am

that is correct