Vitesse brake master cylinder seal replacement

[Robin]

Looks like I've got a very small drip coming out of the master cylinder which I'm assuming means checking/replacing a seal. Is it possible to do this without having to drain/ replace all the fluid and then bleeding the system? Thanks, Robin

[Guest]

Hello Robin.

 

It's a master cylinder off job, sorry.

 

However there are a number of benefits by removing the cylinder:

 

1. you can strip the cylinder to replace all the seals inside (not worth just doing the defective seal)

 

2. the cylinder can be checked for any bore wear

 

3. as the system will need to be bled it is an ideal time to flush it all through with new fluid especially if your brake fluid has been in the "lines" for a few years.

 

One tip I would give is that after you have finished bleeding the system, is to jam the brake pedal down as far as it will go with a piece a piece of wood or similar for 24hrs. This will help to expel any tiny bubbles left in the system and helps to produce an even more effective pedal. 

 

Bearing in mind the brake system is a single line unit, it will also be worth checking the usual suspects for any signs of wear or weeping - for example the rear wheel cylinders.

 

Better to check once and bleed once then have to bleed twice on discovering something else.

 

Good luck.

 

Richard.

[AidanT]

Hi Just mine last weekend after finding a small leak. It's pretty easy once off to strip down. Just tember which bits go in which order and direction, I have been told there are two types. To get the assembly out once the circlip is removed is to tap it firmly against a bench ready to catch the piston etc in the other hand

 

Aidan

[Robin]

Thanks Richard & Aiden

 

Can you recommend a one person brake bleeding kit?

[AidanT]

Get a simple one with a receptical and a one way valve. Draper do one. They can be found on fleabay

 

Aidan

[Guest]

Agree with Aidan. I use this system but still have someone pressing the pedal while I work the nipples and keep an eye on the m/c fluid level which does drop quicker than you would expect !! The benefit of an extra pair of hands is that the assistant can hold the pedal down while you lock off the nipple. 

 

As you are removing the m/c, when you come to bleed the system start with the front brakes first. Once you have cleared the air in the front section refer to the normal bleeding sequence for your car.

 

The rationale behind this is that if you start at the rears you will be pulling the air through the length of the system, ideally you want to discard air closest to the m/c as soon as possible. It speeds up the bleeding sequence considerably.  

 

Of course if you need to remove a rear cylinder then the above advice is no longer applicable !!

 

Regards.

 

Richard.

[Pete Lewis]

Keep the drain tube and bottle up high above the wheels then any bubbles have to go up

 

and less likely to draw air in the bleed nipple threads

 

pete

[Robin]

Great - thanks everyone

[Robin]

Agree with Aidan. I use this system but still have someone pressing the pedal while I work the nipples and keep an eye on the m/c fluid level which does drop quicker than you would expect !! The benefit of an extra pair of hands is that the assistant can hold the pedal down while you lock off the nipple. 

 

As you are removing the m/c, when you come to bleed the system start with the front brakes first. Once you have cleared the air in the front section refer to the normal bleeding sequence for your car.

 

The rationale behind this is that if you start at the rears you will be pulling the air through the length of the system, ideally you want to discard air closest to the m/c as soon as possible. It speeds up the bleeding sequence considerably.  

 

Of course if you need to remove a rear cylinder then the above advice is no longer applicable !!

 

Regards.

 

Richard.

Hi Richard, so in terms of the bleeding sequence I'm assuming it's the following;

 

Offside front, nearside front, nearside rear, offside rear?

 

Also, how much fluid do you think I'll need?

 

 

Robin

[dougbgt6]

I always thought furthest away from the master cylinder first? On mine the pipe runs from the master cylinder to the passenger side then splits between front and rear. So the furthest away is the driver's side rear, then passenger side rear, then driver's side front and finally passenger side front. I'd buy a litre and you should have plenty to spare.

[Guest]

Robin.

 

The sequence Doug has given is correct for 90% of other vehicles which includes the Vitesse.

 

My mentioning the bleeding of the 2x front calipers first is to purely give you the advantage of getting rid of air that is between the m/c and the front calipers nothing more than that. As you are removing the m/c that is where the air will enter first.

 

When you have bleed them and locked off THEN start the correct sequence as in the WSM and as Doug describes.

 

My apologies if I did not word it accurately first time around.

 

If you do not want to bleed the calipers first, then commence the normal bleeding sequence.

 

As Doug says, a litre should be sufficient.

 

Hope that helps and explains better ?? !!

 

Regards.

 

Richard.

[Robin]

Robin.

 

The sequence Doug has given is correct for 90% of other vehicles which includes the Vitesse.

 

My mentioning the bleeding of the 2x front calipers first is to purely give you the advantage of getting rid of air that is between the m/c and the front calipers nothing more than that. As you are removing the m/c that is where the air will enter first.

 

When you have bleed them and locked off THEN start the correct sequence as in the WSM and as Doug describes.

 

My apologies if I did not word it accurately first time around.

 

If you do not want to bleed the calipers first, then commence the normal bleeding sequence.

 

As Doug says, a litre should be sufficient.

 

Hope that helps and explains better ?? !!

 

Regards.

 

Richard.

Great - thanks

[Robin]

One more question ...

 

Just passed the MOT yesterday but the tester said the the rear offside brake was slightly low on pressure - possibly a sticking brake cylinder.

 

As I've got to drain the brake fluid - is it worth replacing the rear brake cylinders at the same time? If so is it a straightforward job?

 

Thanks again

 

 

Robin

[AidanT]

It's not too difficult to do. Just follow the manual I would change both sides though not just the one. The cylinders are not too expensive plus replace the rubber covers and shims that holding them in

 

Aidan

[dougbgt6]

Yes, change both. An easy job although watch out for the brake pipe, quite soft and may not want to separate.   Have you considered silicon brake fluid, dot 5? More expensive initially but as you're supposed to change the old stuff, dot 3 or dot 4, every two years cheaper in the long run. And it doesn't rot the bulk head. Watch out for dot 5.1, it's not silicon, it's the same as the old stuff, why they called it dot 5.1, who knows? Just adds to the confusion!

[AidanT]

Doug

 

Silicon fluid is whole other debate !   

 

Aidan

[Guest]

Hello Robin.

 

Well done on the MOT.

 

Yes, change both - mad not to do that and a very straight forward job.

 

As you will be disconnecting the rear cylinders, do not bother about bleeding the front part of the system. Stick to the sequence given in the WSM.

 

A shot of plus gas a few times or equivalent about 24hrs before commencing the job will help greatly as the bolts & nuts etc will have been prone to all the road grime over the years.

 

Additionally, ENSURE that the spanners you use really do fit tight on to the nuts & bolts as you will require a decent grip to get them shifting and the last thing you need is rounded off nuts - which is probably a very distressing condition   !!

 

Also have a think about the condition of your flexi hoses as over a period of time they deteriorate and can collapse slightly within themselves - this can also lead to low braking efficiency. I changed over to these on Ebay 370625148175 - they are Goodridge hoses but Ian (the seller) does not brand name them. The hoses made a significant upgrade and improvement - just a thought and perhaps worth doing another time. 

 

Reckon that's about enough to get you going; as you are doing the whole bleed system you may wish to have a spare litre of brake fluid on stand-by.

 

With regard to silicone fluid, Aidan is correct it's a whole new issue and to be honest I think I would stick with what you are intending to do.

 

I'm not putting silicone down, as I have that in the Alpine and DOT4 in the Vitesse.

 

Good luck.

 

Richard.

[dougbgt6]

Here is our good friends, Buckeye Triumphs, in depth analysis of brake fluid. Enjoy!

 

http://www.buckeyetriumphs.org/technical/Brakes/Fluid/Fluid.htm

 

 

Richard, Our beloved club shop sells exceptionally good brake hoses.

[Robin]

Thanks to everyone for all the advice

Robin

[Colin Lindsay]

For brake bleeding tools - simplest is best - short plastic pipe with a hole in it, about £1 from auto factors. From personal experience of pumps, vacuum pumps and other assorted gadgets - they're a waste of money. 

 

BTW Dot 5.1 fixes a security flaw in the original 5.0 fluid and should be downloaded as soon as possible.

[dougbgt6]

Yes, I don't get all this fancy brake bleeding kit. Long plastic pipe and jam jar, open the nipple, stamp on the brake 4 or 5 times, run round the back close the nipple. Top up master cylinder, move onto the next one. If brakes are soft, repeat.

 

Colin, 5 & 5.1? You haven't recently upgraded from 8.1 to 10 have you? Time for a lie down in  a darkened room.

[68vitesse]

Not sure what you are saying but Dot 5 is silicone Dot 5.1 is not, they should not be mixed.

 

I use Dot 5 in my Vitesse and have done for years.

 

Regards

 

Paul

[dougbgt6]

Paul, you are correct. If you had read my previous you would know that I know this. Colin and I are bantering. Also If you read the Buckeye Triumph analysis of brake fluid you will know that silicon and the rest don't mix. I f you want to upgrade to silicon just pour it in and bleed our the old stuff. To repeat, they don't mix.