brakes overhaul: now I'm there, DOT silicon ?

rolando38 · Post by **rolando38** » Sun Sep 13, 2015 7:45 am

I finished yesterday the replacement of seized pistons and seals on front brakes

a few pics

anyone for fish soup ?

or crab curry ?

once reassembled, with stainless steel replacement pistons

I found the "2 screwdrivers" method much easier for removal of the pistons than the "compressor blows one in your face" method
:D

now, I'm keen to go for silicon fluid, as I have a good experience on my Mk2 after 5 years (and I know there's always been lots of debate on the topic)

my doubts:

on series 2, the 2 circuits are independent, can I first put DOT5 into front brakes circuit then later do the same on the rear brakes, or do I absolutely have to put silicon in both circuitry at the same time ?

the front circuit is virtually empty, but I still have to flush it with alcohol , right ? (some DOT4 remains in the servo and master cylinder) I also changed the flexible pipes for braided ones so I hope no problem there

Post by **mgcjag** » Sun Sep 13, 2015 5:24 pm

Hi Ronaldo....stick with only one type of fluid, you will complicate things if you mix them.. Steve

rolando38 · Post by **rolando38** » Sun Sep 13, 2015 7:41 pm

for sure, but I would if possible prefer to fill first front circuit with DOT5 silicon, then a few weeks later do the same on rear circuit; would it be possible or do both circuits "mix" at the servo level ?

Post by **1954Etype** » Sun Sep 13, 2015 8:08 pm

Don't do it. You will hear all sorts of stories regarding how silicone causes seals to swell, doesn't lubricate the rubber, gives a soft pedal etc etc.

I have used silicone for years with no problems and use it in customer cars. However, only if all the seals are new and the pipes are either new or have been thoroughly flushed if they have had DOT4 in them.

The manufacturers state that you can replace a system filled with DOT4 with DOT5. I believe this is where the problems start.

Now, this could be utter tosh, so, do you feel lucky.......

rolando38 · Post by **rolando38** » Mon Sep 14, 2015 5:01 am

Ok, I'll stick to DOT4 then
I switched to silicon on my Mk2 but I also had changed the seals of the master cylinder and replaced the servo, which is not needed here on the E-type
and the flushing of the circuit with alcohol resulted in some (maybe 5%) alcohol left in the circuit; so I let you imagined what happened after an intensive use of brakes going down from a pass in the Alps...
but after complete replacement with silicon, I'm very happy with the result 5 years later

abowie · Post by **abowie** » Mon Sep 14, 2015 8:53 am

rolando38 wrote:Ok, I'll stick to DOT4 then

I think this is the best solution for you.

And I am a "dyed in the wool" Dot 5 lover from way back.

If you want to change types of fluid you really need to rebuild the whole system when you do it.

rolando38 · Post by **rolando38** » Mon Sep 14, 2015 1:40 pm

yes, agree
by the way, can I avoid bleeding the rear circuit as I only worked on the front circuit ?
is bleeding rear brakes as complicated on the S2 as on the S1, as there are 2 apertures allowing access to rear calipers ?
(I saw also a nice kit to helps rear brakes bleeding)

abowie · Post by **abowie** » Tue Sep 15, 2015 5:22 am

rolando38 wrote:yes, agree
by the way, can I avoid bleeding the rear circuit as I only worked on the front circuit ?

Yes that should be fine.

rolando38 · Post by **rolando38** » Tue Sep 15, 2015 12:28 pm

thanks Andrew

rolando38 · Post by **rolando38** » Sun Sep 27, 2015 6:55 pm

With new brake pistons and calipers fitted back into place, new greenstuff pads and braided hoses i was expecting a hard pedal and powerful braking but on first few miles it was disappointing with soft pedal on first pressure, then a much harder one.
Initially, before overaul, I had a kick-back in the pedal, now replaced by spongy first press.
To be complete. I must mention That during the bleeding process, the easybleed bottle ran out of liquid therefore there was a fair amont of air injected in the circuit. But I bled twice alter That and now no bubbles coming out
Any idea to solve the issue ?

Post by **mgcjag** » Sun Sep 27, 2015 9:06 pm

Hi Ronaldo....similar problem on this ongoing thread.....you probably still have air in system..Steve
viewtopic.php?t=7760

rolando38 · Post by **rolando38** » Mon Sep 28, 2015 5:00 am

thanks , I read the thread before, but as it seems to be a series 1, I thought things could be different with 2 separate circuits on the S2
will try to bleed the good old way with a chap pressing hard on pedal

Post by **mgcjag** » Mon Sep 28, 2015 8:01 am

Hi Ronaldo.....yes but it is a 4.2 series 1

rolando38 · Post by **rolando38** » Fri Oct 09, 2015 7:33 pm

finished the bleeding this week with help of a friend with good old method;
We also bled the rear brakes although I didn't touch the rear circuitry; a few bubbles came out though, and the fluid colour was a bit dark at start
...and now the pedal is firm and stops where it should

thanks for your advice

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

brakes overhaul: now I'm there, DOT silicon ?

#1 brakes overhaul: now I'm there, DOT silicon ?

#2

#3

#4

#5

#6

#7

#8

#9

#10

#11

#12

#13

#14