Does an overfilled brake fluid reservoir matter?

[andydormer]

Hello all,

Does an overfilled brake fluid reservoir matter?

The reason I ask is my van had new front discs fitted yesterday, immediately before a 125 mile trip from Hayling Island to Taunton. The mechanic also regreased the bearings as they claimed there was some 'play and needed tightening''.

I drove a few miles around the island and worked the brakes with no problems.

25 miles into the trip home a high pitched continuous squeak came from the direction of the front n/s wheel when I went over 50ish mph. If I sped up it stayed, if I took my foot off the accelerator the noise remained until I'd slowed to 45 mph. When I dabbed the brakes the noise stopped immediately - until I went over 50 mph again.

I stopped at the next services and all looked fine (except the speedo cable clip was missing off the grease cap) and the wheel itself was warm to touch. No play in the wheel. Thought maybe brakes needed some more bedding in? But the noise continued.

When I got home I noticed the front wheels were dirty with brake dust and very hot, suggesting brakes to be the noise and not right. Calculations suggest rubbish mpg.

Tonight after work I jacked up both front wheels. No play in bearings and wheels do not turn freely (left worse than right), I can hear the brake pads rubbing on the disc. I then checked the fluid level and it's about a cm above the max level - reading online suggests this is due the the thickness of the new pad pushing fluid back up the system. I will syphon out the excess fluid tomorrow after work and go for a test run.

Has anyone experienced overfilling brake fluid being a problem? Hope it's this simple. Or am I looking at spending the weekend re-doing the work (+ new bearings) I payed the mechanic to do?
Advice appreciated, Andrew

[California Dreamin]

New disc's so OBVIOUSLY, new pads were fitted as well?

It always worries me when I see statements like: The mechanic also regreased the bearings as they claimed there was some 'play and needed tightening'' because:
1) If he fitted new discs he has removed the bearings in their entirety from the old discs and fitted them in the new...So WHY say he has re-greased and taken out play?
2) There should be play..these are taper roller bearings, a small amount of play is essential to allow for expansion.

And yes: very worrying state of affairs if the wheels are binding significantly.
A bit of brake dust is normal, as is a bit of heat after a journey but how hot is hot?
Clip missing of the speedo...not good, needs replacing.
Continuous squeal does sound like brake pads...but the binding may indicate that one or both calliper pistons are seizing (single piston type)
As for the fluid level....well you need a little space in the reservoir to allow for fluid expansion, however, the only harm that overfilling will cause is fluid overflowing and getting on paintwork (it acts like paint stripper)

Martin

[andydormer]

Hi Martin, cheers for the reply. Hadn't thought about caliper pistons, and thinking about it that's where I'll look next.

I just checked the receipt - discs only. That's what the mechanic said it failed the MOT on, causing the brake imbalance. He never mentioned the pads but when I checked them 200 miles ago they looked fine. Strange he didn't notice the pistons when fitting the discs, or is it something that just happens as you drive along.

I checked the bearings before the MOT and thought they were fine, but I plan to replace them now as he probably reused the peening nut (it's not on the receipt). Unfortunately I was working away from home so not around while the work was being done - I trusted the mechanics who have been ok working on our cars before.

How hot is hot? Certainly too hot to touch the wheel. Would this kind of heat have damaged anything?

I've just removed about 60mls of brake fluid from the overfilled reservoir so the level is now at the max. I pumped the brakes a few times then jacked up the nearside front wheel and tried to give it a spin - from a strong heave to get the wheel to rotate it stops almost as soon as I let go. The more I think about it the more likely it is the pistons... Will check the caliper pistons...

Cheers again, Andrew

[weldore]

before you go and strip it all down just check how free the pads are in the calipers.if they are a tight fit when its cold then with heat they will tend to bind in the runners and stay where they are left after the brake is applied.
if its the old brake type then all you need to do is take the wheel off and pull the pins and remove the sprung clip to get at them.if they seem a litle tight in there then get a screw driver and scrape any rust and crap from the runners .if they pull out nice and easy then perhaps look more to the pistons.
just a thought..