Brake pedal pulsing ?

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Brake pedal pulsing ?

Postby Yozza » 27 Jan 2014, 22:48

Ay up,

I have driven my 16" Syncro for the first time since it's had a lot of work done on it's undercarriage. With regard to the brakes they've had new discs, new calliper seals and pads. The rear brakes got stripped down, cleaned and re-fitted.

It's got some serious brake pedal pulsing going on at both low and high speeds. I've checked the discs (inner face) with a DTI for run-out (fine) and also checked to make sure there was no crud between the hub and disc mating faces.

It may be the rears but the MOT man also suggested it was the front when it was on the rolling road.

Any more ideas on this one, I'm head scratching (again). :shock:

Could it something other than the brakes as I've had all suspension and drive line off for resto work.

(It didn't fail the MOT for the brakes either)

Cheerz,
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Re: Brake pedal pulsing ?

Postby ghost123uk » 28 Jan 2014, 09:51

Just shooting in the dark here, but how about this = Brake servo vac pipe ? Reason = apply brake, vacuum in pipe / servo does it's job, but there is a (hypothetical) leak in the system = vacuum drains away and brakes go hard. Nah, as I type this, it is rubbish, I should delete it :? :roll:
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Re: Brake pedal pulsing ?

Postby Yozza » 28 Jan 2014, 11:12

Yer thinking outside the box - keep em coming :ok

I do have black plastic pipe in the engine bay that's not attached but looks like it should be, it's about 6mm OD and there are two others, I suspect it's part of the diff lock vacuum circuit??? I was saving that one for a fresh post. :?
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Re: Brake pedal pulsing ?

Postby marlinowner » 28 Jan 2014, 12:13

Can you feel anything through the handbrake? If you can then its at the back. I had a similar problem after fitting new drums, fortunately it gradually improved and is no longer detectable.
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Re: Brake pedal pulsing ?

Postby Ralf85 » 28 Jan 2014, 12:19

The drum brakes on the back wheels can wear unevenly over a couple of decades. Happened to me some years ago. A new wheel solved the problem for me.
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Re: Brake pedal pulsing ?

Postby Simon Baxter » 28 Jan 2014, 17:21

Judder is usually the drums in my experience.
Maybe they were seized on and someone has had to beat the "pooh" out of them to get them off.
Quite usual, imported vans usually have seized on drums.
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Re: Brake pedal pulsing ?

Postby Yozza » 30 Jan 2014, 21:18

Thanks fellas, I'll try the handbrake test to see if I can feel owt.

:ok
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Re: Brake pedal pulsing ?

Postby syncropatrick » 31 Jan 2014, 12:58

Got a pair of used 16" drums here. Came off my van in Dec only because I had a brand new pair to fit. No known problems with them. Will sell them to you. Let me know.
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Re: Brake pedal pulsing ?

Postby torchy » 31 Jan 2014, 21:12

syncropatrick wrote:Got a pair of used 16" drums here. Came off my van in Dec only because I had a brand new pair to fit. No known problems with them. Will sell them to you. Let me know.

Hay Patrick...if the originals are ok did your new ones fall off a lorry? :ok
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Re: Brake pedal pulsing ?

Postby ..lee.. » 02 Feb 2014, 23:15

I presume you're either decoupled or the cv is knackered ???
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Re: Brake pedal pulsing ?

Postby Yozza » 08 Feb 2014, 16:43

..lee.. wrote:I presume you're either decoupled or the cv is knackered ???


Not decoupled, :shock: are you suggesting that a knackered VC could exhibit the same symtoms :shock: :shock: :shock:
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Re: Brake pedal pulsing ?

Postby Yozza » 08 Feb 2014, 17:01

A bit of an update (after spending all Sat afternoon on the drive) :(

Did the handbrake test and I couldn't feel anything.

Fronts disks removed inspected/measured and all good.

Rear drums have been skimmed by an engineer so I know they're round.

Went for a spin with fingers crosses and hey presto - no change :(

I am now convinced it is something else...

I have never done anything with the (not sure if this is the right term) 'brake regulator', I have seen it underneath but I've never touched it. Could this be a potential contender???
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Re: Brake pedal pulsing ?

Postby Yozza » 17 Feb 2014, 20:20

Update...

Got a chance to have another good look at the fronts, took the wheels off and checked with a DTI on the outer face of the discs.

N/S had a runout of 20thou and O/S 8thou (0.5mm & 0.2mm in new money). :shock: :D

Took them to a local automotive engineers for a measure (double check) and refurb and hey presto £30 later got some straight discs and no pulsing brake pedal.

Just goes to show even though I bought these discs new at Vanfest from a respected supplier it could still be crap!

:ok
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