Sticking brake caliper - possible causes?

TriumphZ3

Dedicated Member
Joined
Aug 2, 2023
Points
39
I've had my 1.9 now for 15 months and twice in that time (today being the second!) the passenger side front brake caliper has seemingly stuck on; loads of burning smell and a lot of heat. Last time it happened, about July time, I stripped down the caliper, cleaned all and rebuilt. I've no idea why it's doing this as all is clean, rust-free and sliding freely, so it seems to me it's a fluid problem. I'm going to replace the flexible hoses at the calipers to see if that cures it, the hose may be collapsing inside, but before I do this is there any other possible cause I should look at?
 

Nodzed

Zorg Expert (II)
Supporter
British Zeds
M Power
Joined
Feb 18, 2016
Points
231
Location
Forest of Dean, Gloucestershire, England
Model of Z
Z3M Imola and Z4 (e89)
Most likely the piston is corroded and sticking. New pistons and a reseal is a cheap and easy DIY job. You could also renew the slider rubbers while it off.
 

Mint

Zorg Expert (I)
Supporter
British Zeds
East Anglian Crew
Joined
Sep 23, 2012
Points
222
Location
Stafford
Model of Z
2.2 & 3.0 Sport
The fronts are not too expensive to replace... the rears however :whistle:
 

TriumphZ3

Dedicated Member
Joined
Aug 2, 2023
Points
39
Any recommended suppliers for firstly piston and seals but then if reasonable, a complete caliper? No racing or rallying, just normal everyday driving.
 

Nodzed

Zorg Expert (II)
Supporter
British Zeds
M Power
Joined
Feb 18, 2016
Points
231
Location
Forest of Dean, Gloucestershire, England
Model of Z
Z3M Imola and Z4 (e89)

I wouldn't recommend anywhere else for brake kits.
 

Andyboy

Zorg Guru (II)
Joined
Jun 2, 2019
Points
119
Location
SHEFFIELD
A reconditioned front caliper is 25 quid or so. Not worth messing around with seal kits etc.

You may find the brake hose is collapsing internally and causing the brake to stick on. A hose is a tenner.
 

t-tony

Zorg Expert (II)
Supporter
British Zeds
#ZedShed
Joined
Dec 31, 2013
Points
226
Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
Nearly all motor factors. EBay, Amazon, etc.etc.

Tony.
 

Mint

Zorg Expert (I)
Supporter
British Zeds
East Anglian Crew
Joined
Sep 23, 2012
Points
222
Location
Stafford
Model of Z
2.2 & 3.0 Sport
Can't remember the seller I used on the bay but just had a quick look and a pair of fronts are available for just shy of £50.
 

TriumphZ3

Dedicated Member
Joined
Aug 2, 2023
Points
39
Thanks guys, it's now just a case of fighting my way through all the bumf "fits XXX, XXX, XXX up to 1997"that I've already found on eBay sellers just now. Why do they make it so difficult for a daft old pensioner to identify the correct part? :)
 

t-tony

Zorg Expert (II)
Supporter
British Zeds
#ZedShed
Joined
Dec 31, 2013
Points
226
Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
Does your car have solid discs or vented? Measure the diameter. Armed with this info, along with year and engine size, go to Euro Car Parts, or remove the calliper and take it with you.

Tony.
 

Andyboy

Zorg Guru (II)
Joined
Jun 2, 2019
Points
119
Location
SHEFFIELD
The difference is in the rear track. The Z3 1.9 used Compact rear trailing arms, driveshafts and caliper carriers but the rear hubs are slightly wider, the discs have a deeper 'bell' and the caliper housings are different.
 

mikeyH

Dedicated Member
British Zeds
Joined
Mar 8, 2024
Points
28
Location
South Devon
Model of Z
2.2 Z4 E85
Got my offside front from Eurocar parts and the near side front from Halfords a while ago when they had a promotion going. Just in case. :thumbsup:
 

TriumphZ3

Dedicated Member
Joined
Aug 2, 2023
Points
39
Took the plunge and bought online, £31.99 including postage. Still waiting on delivery almost a week later, though. My local Autofactors had a replacement hose, so that will be changed as well. I never thought to ask them about calipers, as I'd bought that one already, but they have everything else. This has been an intermittent fault; I bought the Z3 15 months ago and the friend who came with me on the test drive said he thought that one of the calipers was sticking, but it sailed through MOT a month later with no worries. It stuck on again maybe ten months later which was when I dismantled it and freed everything up. This time I'll do it properly and replace everything.
 
Top