The Brick-yard Homepage Brickwerks
Forum Home Forum Home > LT, Crafter & Sprinter Section > LT2 and sprinter forum
  New Posts New Posts RSS Feed - 2004 2.5 tdi VW lt 28 brake issues
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

2004 2.5 tdi VW lt 28 brake issues

 Post Reply Post Reply Page  <12
Author
Message
mojo View Drop Down
Groupie
Groupie


Joined: 04 Dec 11
Location: Liverpool
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote mojo Quote  Post ReplyReply Direct Link To This Post Posted: 24 Nov 19 at 20:48
I have a feeling the previous owner may have removed a bulb or two from the dash. How long have you had the van?
There should be four abs sensors and the pain in the arse bit is they are a nightmare to remove (when they're fitted) and they are hard wired into the ecu, when replacing them the original wiring has to be cut and then join the new wiring/sensor. I fitted a weatherproof connector plug on my new sensor rather than hardwire it up again just for future convenience if the knuckle ever has to come off. I couldn't remember which warning light came on when the sensor was removed so I've just unplugged the abs sensor and checked, it's the immobiliser light (the yellow light on the right with the circular arrow) which comes on and stays on solid.
2006 LT35 TDI 109 AVR
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 19 at 15:12
Brilliant thank you, I'll take the dash apart soon.

I've now replaced the master cylinder, the disks, pads and all calipers, the load compensating valve. Still the same.

With the vacuum entirely disconnected the brakes are about the same as with it on. I've bled and bled the system now. Its had around 3l of fluid.

I have vcds on the way but its coming from Australia so it may take a while.

The pedal falls away under pressure and it's not safe to be out on the road currently, it's like the brakes have no force at all, I'm running out of patience now Haha.
Thanks for your continuing help here 
Simon 
SWB VW LT 28 2.5TDI
Back to Top
mojo View Drop Down
Groupie
Groupie


Joined: 04 Dec 11
Location: Liverpool
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote mojo Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 19 at 20:20
The only thing left is the servo! If that doesn't sort it.... a can of petrol and box of swan vestas should haha.

If you pump the brake pedal with the engine off does it stiffen up, if it does, keep your foot on the pedal and start the engine, you should feel the vacuum assistance help draw the pedal lower.
2006 LT35 TDI 109 AVR
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Dec 19 at 21:16
Yup pedal goes solid with the engine off, and the pedal creeps down with the engine started. Hopefully when vcds gets here I can properly purge the abs pump. I'm wondering if the new master cylinder could be knackered.
It doesn't feel good trying to stop it, theres just no force there at all.

Thanks for replying, I thought about the can of petrol solution too haha
SWB VW LT 28 2.5TDI
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Dec 19 at 14:00
Bit of an update, changed the vacuum pump, and bled the brakes again, got some very tiny bubbles out of the abs pump and the rear calipers.

I have vcds now but when I try to connect to the abs pump I get an error saying "no response from controller"

The dash lights were unplugged for the abs, and theres 2 other ones there now with no bulbs but I'm not sure where they go.

Took it out for a spin yesterday, a lot better brakes but not enough to even set the abs off on gravel, still not enough force there.

The front os wheel bearing has had the same "care" from the previous bodger and the wobbles through the disk makes a noticeable bang as the caliper moves around on the sliders, its either a replacement used hub or attempt to change the bearing? 

I don't have access to a press but I have seen lt35 hubs on Ebay. 

Thanks for your help yet again 
SWB VW LT 28 2.5TDI
Back to Top
mojo View Drop Down
Groupie
Groupie


Joined: 04 Dec 11
Location: Liverpool
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote mojo Quote  Post ReplyReply Direct Link To This Post Posted: 22 Dec 19 at 11:32
Sorry mate I meant to reply to last message, vcds won't talk to the abs on these. VCDS only talks to the immobiliser and engine. Think it's the fact that a lot of it is mercedes build. I took my van into vw commercial to code new dash clocks with rev counter but they couldn't do it, they started getting old dusty computers out of the stores cupboard to try them but had no joy. It went from a half hour job to three hours to 'leave it with for a couple of days.....and we'll bill you accordingly @ £100 per hour' errrrrrm no thanks chaps!

The abs system won't work without the wheel speed sensors fitted but abs shouldn't affect the normal operation of the brakes as a safety concern. Did you retrieve any fault codes?
Pretty sure you should have the same lights on ignition as in the picture I posted, some bulb slots will be empty as they are for things like 4x4, power take off, etc.
The front wheel bearings are adjustable so it may just be a case of tightening them on by the screw and clamp nut. Probably best to remove them, clean and inspect them, regrease and refit them if ok. To do them to spec you'd need a dial guage indicator and mount.
Also meant to say to bleed the clutch slave cylinder on the gearbox just as a matter of service to the fluid system, you'll know the whole system is flushed and fluid renewed. The one other tech spec on bleeding the brakes was to operate the load adjustment lever when bleeding (which I never done) but brakes are fine.    
2006 LT35 TDI 109 AVR
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 25 Dec 19 at 14:42
Ah bugger, I was hoping that it would help having vcds. The only fault codes I got were start of injection timing, an egr ground fault and fuel shut off solenoid. 
I was giving the compensating valve a wiggle, but not much of a difference.
I'm not sure what the valve spring should look like when it's in, I don't have any idea of the weight at the moment, if I get enough brakes I'll get it weighed,  but it definitely seems to brake better in reverse than 1st.

Happy xmas 
Simon 
SWB VW LT 28 2.5TDI
Back to Top
mojo View Drop Down
Groupie
Groupie


Joined: 04 Dec 11
Location: Liverpool
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote mojo Quote  Post ReplyReply Direct Link To This Post Posted: 27 Dec 19 at 07:55
VCDS will be invaluable once you've sorted the brakes.
The only thing regarding the brake regulator I would worry about now is that there is no tension on the control rod. The regulator when applied (heavy load) reduces braking pressure to avoid overbraking of the rear wheels. Tech states to ensure the braking system is working fine before adjusting the regulator.
I'd concentrate on sorting the wheel bearings as it could be them affecting the geometry of the brakes and if they are causing clunking when applying the brakes as you say it sounds like they are well out. Play in the wheel bearing should be 0.02 - 0.04mm (hence the dial guage), so if you can feel the play by hand it's out of spec. This could account for the better braking in reverse. I've seen many mechanics just tighten the wheel bearing with pliers hand tight and that's their spec! You could try this for now to see if it is loose and makes any difference in braking. Wheel off - bearing cap off - loosen allen head lock screw - tighten clamp nut - hold nut in place - tighten lock screw - refit bearing cap.


Are there any signs of uneven wear on the brake discs, you could spray them with some water and leave them for a day or two to get some surface rust, drive the van a little - apply the brakes to a stop and then check for any wear patterns where the rust has been removed or remains. If you still have the old disks they can tell a story.

2006 LT35 TDI 109 AVR
Back to Top
Phaeton_Buggy View Drop Down
Not Quite Newbie
Not Quite Newbie


Joined: 12 Nov 19
Location: Northish
Status: Offline
Points: 14
Post Options Post Options   Thanks (0) Thanks(0)   Quote Phaeton_Buggy Quote  Post ReplyReply Direct Link To This Post Posted: 29 Dec 19 at 00:32
Total newbie here so feel free to ignore, does yours have a weight regulator on the back axle?
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 29 Dec 19 at 00:45
Yes mate, I took a very knackered and welded shut one off the back, it's got a new one now. 
I've got a nearly full conversion in the back so it needs weighing on both axles to set up right. 
I'm going to inspect the bearing tomorrow, but I only have a low profile trolley Jack which is my dads for his BMW so I'm worried about breaking it. 
The bearing even not at speed or heavy braking, clunks the caliper around like a pr**k.
I'm worried I'm just replacing parts for nothing but the brake pedal feels like theres no effort from the van.
Simon
SWB VW LT 28 2.5TDI
Back to Top
Phaeton_Buggy View Drop Down
Not Quite Newbie
Not Quite Newbie


Joined: 12 Nov 19
Location: Northish
Status: Offline
Points: 14
Post Options Post Options   Thanks (0) Thanks(0)   Quote Phaeton_Buggy Quote  Post ReplyReply Direct Link To This Post Posted: 29 Dec 19 at 09:11
Sons brakes are not great although they sound better than yours, we need to have a look at his but the weather is not fit at the moment (no garage) another thing to check is the flexi hoses, get somebody to press the brake pedal & you hold each flexi in turn they shouldn't expand.
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (1) Thanks(1)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jan 20 at 15:15
So the brakes are working!!!! The wheel bearing wasn't put together properly, huge socket and a hammer and a clunk. Put it back together again and its working better!! 

The brakes now really do work properly, the whole van shifts now.

Thanks for all your help here!!

If I ever meet you I owe you a drink or 2!!

I'll now start another post for my bloody steering!!!

Simon 
SWB VW LT 28 2.5TDI
Back to Top
mojo View Drop Down
Groupie
Groupie


Joined: 04 Dec 11
Location: Liverpool
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote mojo Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jan 20 at 17:16
So that was you celebrating with all those fireworks the other night!LOL

Glad it's sorted........ finally.



2006 LT35 TDI 109 AVR
Back to Top
Cornwall87 View Drop Down
Groupie
Groupie


Joined: 18 Oct 19
Location: cornwall uk
Status: Offline
Points: 50
Post Options Post Options   Thanks (0) Thanks(0)   Quote Cornwall87 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jan 20 at 17:23
Haha yeah I went all out.

Thank you for your help and patience 
Simon 
SWB VW LT 28 2.5TDI
Back to Top
 Post Reply Post Reply Page  <12
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

The WebThis site