A few (hopefully) quick questions

OK gaz,I will step up first.
Tyres lumps & bulges are, as far as I am aware are the same thing.
Brakes
When assessing imbalance you should first check for maximum effort & then run both rollers to around 75% of the lower Max effort. So if say n/s Max effort is 380kg & o/s is 300kg take up both rollers till the o/s is around 225kg, around 75% remember. This is is the same for each axle.
If when carrying out the imbalance check there is a difference of around 30 or more % I would consider using the "uneven application" or "uneven release" rfr.
Nearly forgot, the "brake binding" rfr should only be used if your brake tester shows a brake effort without a brake being applied.
Hope that helps, no doubt there will be more posts on this !!

ivor, if lumps and bulges are the same thing why have two seperate RfR's? Which do you use?

For imbalance. That sounds more like the manual but still doesn't seem like what it implies? Is 75%, as the manual states, stopping close to lockout?

When I first started testing I was in an ATL station so I went by what it says I should do. The imbalance readings were taken at around the 150kg mark (about the point when most cars get thrown out the rollers when testing the front) so I've continued that on my current set of manual rollers.

At what kg force would you start to think about failing vehicle for a significant bind?

A lump is in the tread, a bulge is in the sidewall.

The machine onlty lets you fail balance if your lockout figures are bad enough. I haven't had a car yet which wouldn't lock both fronts so my "application is uneven " button gets lots of use.

We are supposed to spin both rollers, take brakes to about 75% of lock-out and then check for judder fluctuation. then release and re-apply to lockout. My crystal ball is broken so I don't know where 75% will be so I measure individual locks, then do the maths in my head. However this does mean the figures I enter on the device do not reflect braking performance but tyre grip. In my opinion 150kg is not enough on a T% transporter that locks at 580/600kg

I want to see about 30-40 kg to justify a bind. If the pads are stuck on when I spin the wheel it's obvious to me (but not to some other people) that the pads have restricted free movement

Sorry mate, try this one?: mattersoftesting.blog.gov.uk/2013/06/27/changes-made-to-brake-performance-test/

A bulge is more rounded and uniformed where as a lump has no shape at all.
Bulge or lump can be found any where on a tyre depends on the type of defect, most times bulges are found on sidewalls , but your may come across lump on a sidewall like I said which does not look like a bulge due to its shape.
Very rare I use the lump rfr.

A significant bind on one vehicle may not be significant on a another vehicle such as big cars and vans etc.
You will need to use your judgement and Experiance on this issue as there is no defined figure.
Bind is determined by the rollers ,not when jacked
If the bind is so severe then increase and decrease will normally provide a fail anyway.
The increase/decrease rfr is there to give and indication how the mechanical side of the brakes are performing.
Once again use your judgement and Experiance.

As Ivor said its important to chock the wheels to prevent the vehicle jumping out the rollers.

nitros44, you lump vs bulge description sounds quite plausible.

It's seems everybody is in agreement that to use the significant bind RfR, it must be shown on the rollers. In the past, I've had a binds so bad that I've found it difficult to turn the wheel but nothing significant has shown up on the rollers but I've still used the bind RFR.

I've also used the manual imbalance RfR if my rollers show over 30%. I guess I should be using the uneven application/release instead? Problem is my rollers only show up the % at it's greatest point, not if its achieved on application or release. Have I just to take an educated guess on which it is? When running both rollers together on the front I always have the handbrake on. I've never had a car jump out on the back.

I've always been a bit confused as to why there are two seperate RfR's for dust covers. I've used both. If it looks like a clean cut which it usually is I'll use the damaged RfR, if the rest of the boot is all cracked and perished where one part is burst open I'll use the deteriated RfR.

Ok, so I guess VOSA forgot to remove the imbalance RfR with all the updates then?

I'll use the uneven application/release RfR from now on. At least it gives a better indication of what's actually going on with the brakes.

What I don't get is with VOSA wanting the same testing methods across every site, how was it OK for me to test imbalance to 150kg on the ATL rollers but not on my current manual ones? Cars that would pass the ATL may well fail the manual test.

On single circuit brakes you have to manually fail secondary brake imbalance if I remember correctly