"Poor" brakes on 6.9

[Styria]

Driving home from my storage area, a distance of some thirty odd kilometers, I experienced slight brake fade, and a spongy pedal, when getting close to home. It only ever happened twice, but often enough, and significant, to cause me to put my thinking cap on. I had looked at the brake pads on the right hand side when I replaced the hydraulic hose, and although they were worn fairly well, I felt that there was no need to replace them.

Thus,when I experienced the latest brake sponginess, it was time to again look at the brakes. It was just by chance that the left front was more accessible, and to my surprise, the pads were just about completely worn down. I had a set of dust free pads on hand, fitted those, and the brakes are back to normal - in other words, quite efficient. Regards Styria

 

[Oversize]

Styria I've never heard of W116 braking issues when the system is operating normally; they are quite effective and not underbraked. Yes the calipers can seize, which is easy to spot as she'll pull to one side under brakes. The calipers are pretty simple and bulletproof. It's quite easy to rebuild them and add new seals.

An interesting issue is what solvent should be used to clean and repair the calipers. I've always used methylated spirits to lubricate fine wet and dry sandpaper (to hone the bores) and rinse parts off, prior to blowing off with compressed air. My reasoning has been that metho absorbs water and evaporates quickly. Thus it should remove any water residue that may still remain in the assembly. However I've heard that metho can damage the seals and only brake fluid will suffice for cleaning / honing. Trouble is BF is extremely messy, expensive and if it gets onto painted surfaces the result can be nothing short of disasterous!

I've also heard that you can upgrade the W116 brakes to W126, but it's not as simple as swapping rotors and calipers. Plus it's not really necessary anyway as the original ones are more than adequate. My AU II on the other hand is nothing short of abysmal and even after changing to slotted, brand name rotors and quality pads, nothing has changed. For the life of me I don't know why they are so bad (they seem big enough) and the only way I can see to fix them is by fitting BA brakes, or Brembos at considerable cost...

 

[Tony66_au]

2 pac paint is ok with brake fluid as Brake fluid is not as corrosive as it used to be.

That said Brake fluid is Hydroscopic and once you have opened a bottle it should be used and discarded within a week of opening.

Ballooning hoses are also an issue and otherwise visually fine hoses can rupture between the layers and balloon under pressure, Id also be aware of water absorption when a car sits especially in a concrete lockup.

When water gets into brake systems it can boil very quickly and will usually head for the calliper reservoir where it displaces brake fluid and causes failure.

So id be flushing the fluid on any car stored in a normal manner (IE in a non controlled environment) especially considering the weather we have experienced this last month.

I flush mine as a matter of course once a year and for the time and effort I believe it has saved me thousands on repairs and failures.

 

[Styria]

Thanks for your advice. I had noticed that Gleaming Beauty had been pulling just a little to the left, and additionally there were always more deposits on the left wheel compared with the right. That would indicate slight sticking of the caliper, and I took note of a 'sudden' movement when I pushed it back in to fit the new pads. So it all seems to make sense.

One other important observation. One should always place some cloth over the brake reservoir cap, because brake fluid will be pushed out when the calipers are pushed back in. If the brakefluid spurts out far enough, it can damage your paintwork. I was lucky this time, but it caught me by surprise. I should have known better. Regards Styia

 

[Helmet]

I would also check the rear calipers, If one is seized it will overheat very quickly causing fluid to boil and soft brake pedal. Remember that the the rear brakes apply first when you hit the brake pedal.

 

[Oversize]

I usually take off the cap and place it over the open reservior (sometimes with a rag as well), to avoid the jet of brake fluid spraying the underside of the bonnet and all over the guards. I also use guard covers which helps! If the reservior's full and I intend to change front pads (especially), I drain out some of the brake fluid as it's highly likely it'll overflow.

It may also pay to change the fluid altogether....

 

[Styria]

Hi guys, some very sound rationale. I have to admit that I was not aware of the rear brakes coming on first. I suspect that with the long lay-off of just about twelve months due to respray and re-assembly, the calipers could well have decided to become lazy. I was also surprised at the bit of surface rust on the calipers themselves after I removed the pads. I did spray some Inox onto the dust seals and calipers in an effort to free up any stickiness. Time will tell if that works. Regards Styria

 

[Tony66_au]

Whenever I work on a brake system I drag out the turkey baster and simply suck half the brake fluid from the reservoir.

If im cranking a caliper back I crack the bleeded nipple and run a hose from it into a jar of brake fluid so it doesnt push the crud from a possibly faulty caliper back into the master cyl and cause even more havoc.

Ive flushed lines on cars a few times and the amount of crud that spews forth is disturbing.

Tony

 

[Michel]

What's happened to your cars??? they seem distorted.. LOL

 

[Tony66_au]

Michel, Long story short?

I squished em to make em fit and I still cant put em where I want to.


Better?

 

[Oversize]

Thank gosh, I thought my eyes were going!!! Either that or you'd found the very rare SEL(L) models!!!

 

[Tony66_au]

Well the TE is as long as the SE Mark.......

I wanted to replace my Text Sig line with a photo using an IMG link, but I cant because of size restrictions even if i shrink and crop the file.

So I was trying something else but I had to ruin the image to make it work.

So I left it for now.

 

[Michel]

Changing the aspect of a pic can do some serious distortion!
I feel better now

 

[Oversize]

Try pic compression using MS Office Picture Manager....

BTW Tony I know I've said it before but those gunmetal grey Bundts look really good!!!

 

[Tony66_au]

Changing the aspect of a pic can do some serious distortion!
I feel better now

LOL because i posted the antidote?

Amazing how some compression will bugger even a 10 megapixel/5 meg file.

Try pic compression using MS Office Picture Manager....

BTW Tony I know I've said it before but those gunmetal grey Bundts look really good!!!

Honestly Mark I hate MS Office and dont have it on my machine, Jenn has it but I use Corel Photo-paint usually, this time however I used Paintshop pro.

As for the Bundts?

Alex's idea and execution mate, But they need to be stripped and redone and will be redone in Gunmetal again.

Just seems to go well with the green eh?