Brake Fluid change ( W203 )

[Stompbox]

Speaking of problems with carrying out work on brakes, and the mention above of seized bleed nipples - I just put my C220 CDi coupe (2006) W202 in to the local independent Mercedes dealer to get the ATF fluid and filter changed, plus the brake fluid changed - they quoted £40 plus vat for the brake fluid.
The ATF & filter went ok as did the front brake circuit. The back brakes however could not be done as the brake nipples are seized, they said, and quoted a total of £412.75 for fitting new calipers!!!! EEK.
Now as I have time to prepare and there is no rush, since the brakes are, in fact OK, it's just the fluid change I wanted to get done, can I maybe apply a penetrating and release fluid - ( I have some Looz-N-It which I've used on old motorbikes, or how about Holts Release Spray?) to the nipples at home and give them a good soaking and allow time for the fluid to work, then have a new pair of bleed nipples "on standby" to fit if the old ones won't come out without shearing?
If they do, then, with the nipples being hollow, can a bolt extractor be screwed straight in to the bottom half of the old, sheared nipple?
Has anyone here had experience of dealing with this problem?

 

[EmilysDad]

.... can I maybe apply a penetrating and release fluid - ( I have some Looz-N-It which I've used on old motorbikes, or how about Holts Release Spray?) to the nipples at home and give them a good soaking and allow time for the fluid to work, then have a new pair of bleed nipples "on standby" to fit if the old ones won't come out without shearing?
If they do, then, with the nipples being hollow, can a bolt extractor be screwed straight in to the bottom half of the old, sheared nipple?
Has anyone here had experience of dealing with this problem?

I'd be doing exactly as you've described & judicious use of a small hammer. The trouble with Eazi-out stud exractors is that they tend to swell the nipple in the caliper which is obviously the opposite of what you want. I have drilled them out in the past, though using a milling machine which gives a bit more control.
I'd be very reluctant to have to replace a caliper for the sake of a siezed bleed nipple.

 

[Wighty]

Speaking of problems with carrying out work on brakes, and the mention above of seized bleed nipples - I just put my C220 CDi coupe (2006) W202 in to the local independent Mercedes dealer to get the ATF fluid and filter changed, plus the brake fluid changed - they quoted £40 plus vat for the brake fluid.
The ATF & filter went ok as did the front brake circuit. The back brakes however could not be done as the brake nipples are seized, they said, and quoted a total of £412.75 for fitting new calipers!!!! EEK.
Now as I have time to prepare and there is no rush, since the brakes are, in fact OK, it's just the fluid change I wanted to get done, can I maybe apply a penetrating and release fluid - ( I have some Looz-N-It which I've used on old motorbikes, or how about Holts Release Spray?) to the nipples at home and give them a good soaking and allow time for the fluid to work, then have a new pair of bleed nipples "on standby" to fit if the old ones won't come out without shearing?
If they do, then, with the nipples being hollow, can a bolt extractor be screwed straight in to the bottom half of the old, sheared nipple?
Has anyone here had experience of dealing with this problem?

Can you use something like duct tape to create an edge around the nipples so that the release fluid can be held there like a bath around the nipple for 24 hours or longer to give it more time to work ?

 

[EmilysDad]

Can you use something like duct tape to create an edge around the nipples so that the release fluid can be held there like a bath around the nipple for 24 hours or longer to give it more time to work ?

Plasticene or Bluetac is ideal

 

[Stompbox]

Thanks for that. I'll have a look at creating a little "reservoir" round them. I saw reference to judicious use of a hammer - maybe put a good fitting socket on and tap it, do you mean?
I do have an impact screwdriver that will fit 3/8" drive sockets - if there's room to fit it - and to hit it - might that b an idea after say 2 hours of submersing the bleed nipple in a release agent?

 

[EmilysDad]

Thanks for that. I'll have a look at creating a little "reservoir" round them. I saw reference to judicious use of a hammer - maybe put a good fitting socket on and tap it, do you mean?
I do have an impact screwdriver that will fit 3/8" drive sockets - if there's room to fit it - and to hit it - might that b an idea after say 2 hours of submersing the bleed nipple in a release agent?

I mean to gently tap the nipple on the end .... the shock will often help. Don't knock 7 bells out of it though

 

[umblecumbuz]

I fear the worst.
In my limited experience, once a nipple is well and truly seized to the point that reasonable force with tight fitting tools won't budge it, it will sheer before loosening. Unfortunately, these nipples are frail and hollow little things, with a narrow neck that is a built in weak spot.
There is always the possibility of bleeding the system by cracking open the flexihose union nearest to the caliper. Not ideal, but a good port in a storm.

 

[EmilysDad]

I fear the worst.
In my limited experience, once a nipple is well and truly seized to the point that reasonable force with tight fitting tools won't budge it, it will sheer before loosening. Unfortunately, these nipples are frail and hollow little things, with a narrow neck that is a built in weak spot.
There is always the possibility of bleeding the system by cracking open the flexihose union nearest to the caliper. Not ideal, but a good port in a storm.

Agreed, but as Stompbox implies, fitting a new/fresh/refurb'd caliper for the sake of a siezed/sheared nipple seem excessive.

 

[Stompbox]

I know - I'm tempted just to leave it "as it is" since the brakes are OK - it's just to change the fluid, and at least the front brakes have been done, which handle the lions share of the braking effort.
It is just that there is a small voice saying "Hey you can do this".... or, at least, loosen the old ones and then get it bled/changed professionally.
Another way would be secondhand calipers cleaned & fitted with new piston seals & pads.

 

[umblecumbuz]

Agreed, but as Stompbox implies, fitting a new/fresh/refurb'd caliper for the sake of a siezed/sheared nipple seem excessive.

That's why I suggested the 'port in a storm' idea. It saves replacing the caliper if the nipple breaks.
Problem with buying a used caliper off the Bay is that they might be for sale precisely because the seller couldn't undo the nipple!

 

[EmilysDad]

I know - I'm tempted just to leave it "as it is" since the brakes are OK - it's just to change the fluid, and at least the front brakes have been done, which handle the lions share of the braking effort.
It is just that there is a small voice saying "Hey you can do this".... or, at least, loosen the old ones and then get it bled/changed professionally.
Another way would be secondhand calipers cleaned & fitted with new piston seals & pads.

If you shear it, I'll drill it out for you

 

[Stompbox]

Well that really is a very kind offer. I see you're in Bury - I'm in Royton, so not too far.
I'll see if I can get a spare pair of new bleed nipples first, and it may be a few weeks before I get around to looking at it, if you're serious.
In the meantime I had a look at the rear calipers - the nipples stick out of the back of the calipers horizontally so cant really build a "reservoir" round them - at least not at first glance.
I could wire brush them and then just keep applying some of the release spray that I've got. Can't do any harm.

 

[EmilysDad]

Well that really is a very kind offer. I see you're in Bury - I'm in Royton, so not too far.
I'll see if I can get a spare pair of new bleed nipples first, and it may be a few weeks before I get around to looking at it, if you're serious.
In the meantime I had a look at the rear calipers - the nipples stick out of the back of the calipers horizontally so cant really build a "reservoir" round them - at least not at first glance.
I could wire brush them and then just keep applying some of the release spray that I've got. Can't do any harm.

Yes, I'm serious, but if it does come to having to drill them out, it'd be best done off the car so that would obviously require the union undoing which can also be a problem.
Liberal application of Plusgas/etc would be good.

 

[Stompbox]

Maybe new flexible hoses at the same time then.
Are the "Pagid" brand that Euro Car Parts sell OK?

 

[EmilysDad]

Maybe new flexible hoses at the same time then.
Are the "Pagid" brand that Euro Car Parts sell OK?

Pass? Last flexi hoses I bought were for a crappy Astra I had.

 

[John Laidlaw]

Hoses are much of a muchness when it comes to these unless you’re looking high performance braided like Goodrich...they should be fine

 

[Stompbox]

Or these pattern calipers?
https://www.ebay.co.uk/itm/BRAKE-CA...&itm=371929825303&_trksid=p5411.c100167.m2940