Rear Disc Conversion Questions

Good Morning Folks,

I have been trying to read up on rear disc conversions. My Plan is to use ST150 front brakes and so plan to balance the rear using the brakes from the same car ie 260mm rear discs. The machining side of things I think I have got covered from the guide already on here, however to avoid machining a pocket into the spindles to accept the puma ABS sensor does anyone know the part number or a source for the escort estate ABS sensor they used on the FRP?

I had also spotted a comment somewhere that the handbrake may rub on the rear beam when using the smaller 260mm rear discs. Does anyone have any experience of this? It seems to be an isolated comment I can’t find anyone else having issues with.

Cheers
Paul Z

Hi Paul!

I think both tuonokid and XAF have used the escort loom/sensors. Hopefully they will see this and be able to help you out with the specifics!

Good luck, and maybe you could put a short guide together with all the bits and a photo or two when you're done?

Been a while since a guide was written here

Red.

The part number for the straight sensor FRP/Escort estate rear ABS loom is: 1011582

PaulZ said:

Good Morning Folks,

I have been trying to read up on rear disc conversions. My Plan is to use ST150 front brakes and so plan to balance the rear using the brakes from the same car ie 260mm rear discs. The machining side of things I think I have got covered from the guide already on here, however to avoid machining a pocket into the spindles to accept the puma ABS sensor does anyone know the part number or a source for the escort estate ABS sensor they used on the FRP?

I had also spotted a comment somewhere that the handbrake may rub on the rear beam when using the smaller 260mm rear discs. Does anyone have any experience of this? It seems to be an isolated comment I can’t find anyone else having issues with.

Cheers
Paul Z

Click to expand...

Hi Paul,

I have done exactly what you plan.
The puller for the hand brake at rear discs will hit against the rear beam. You will need machining either the beam, or the puller. I opted for the beam as it is not under stress there at all (you will see when you bolt everything together).

I think you may have misunderstood the machining the spindles process here. You have to do it to be able to position the sensors correctly, it has nothing to do with using the original puma, or escort sensors. The differences are that puma ones have angled output, and the escort ones are straight. This is important just in case you decide to use some spacers (straight sensors enable to use as much as you want, the angled max out at 10 mm or so) But you will have to machine the spindles in any case

Thanks Red. I was planning to knock together some machining drawings and list the components I have used to get it to work. That way it should be a lot easier for people to get the bits they need made up ready and then use the other guide for fitting the parts after.

Thanks CherryVimto. I will get one ordered.

Hi Wild E.
Didn’t the FRP use the same hub/disc setup but no mention of the handbrake mechanism clashing with the rear beam or being modified items? Any ideas what might be different between the two? Also I don’t suppose you have a picture of where/what you have machined on the rear beam do you?

I am aware you have to machine the spindles either way in order to fit the sensors but I was under the impression if you used the straight sensors you don’t have to machine a recessed pocket for the ABS sensor as the FRP spindles don’t have that feature machined into them. Obviously I haven’t done this so could be wrong hence why I ask the question. I am just sceptical of machining a pocket into the spindle when so much load is placed through that area of the car.

Cheers for all the replies so far.
Paul Z

I really can't comment on what has Tickford used for FRP. I used focus rear brake setup and that problem appeared. Nothin' major, really, that will be the least of your worries, trust me.

Now, regarding the sensors. You will have to machine spindles a bit; check my thread, there are two procedures I did, I would recommend the latter one as it involves minimum machining and it is not a pocket, just slight grinding off

direct link for the how to: https://www.projectpuma.com/viewtopic.php?p=302532#p302532

If the Ford loom is unavailable or too dear the equivalent intermotor one is 60020.
Barry

Thanks Wild E, Any chance you could take a picture of the area you modified on the beam? Thanks for your comments to but in my view removing material across the whole back face is probably worse than the pocket method. The machining isn't my issue cause I can chuck it on a mill and do it properly I am just hesitant to do so and since it appears FRP spindles were modified without doing this I'd like to replicate it if I can.

Thanks Tuonokid. Did you use the same method as Wild E in your conversion?

Cheers
Paul Z

Pretty much, I think Sinisa and I were doing the conversion at the same time so we replied to each other on the subject. A couple of other points though, if you use Focus ST170 discs and calipers on the rear there are no fouling issues, I agree with you about machining the whole back face of the spindle, and I wouldn't be surprised to find out that on the FRP pockets have been machined into the rear of the spindles but only a FRP owner can confirm that.
Barry

Thanks for the reply. Hopefully someone with an FRP can confirm either way then I'll go from there I think.

Cheers
Paul Z

PaulZ said:

in my view removing material across the whole back face is probably worse than the pocket method

Click to expand...

You are not taking the material across he whole face, just the area where sensor sits. You have to achieve a gap of 0,6 mm between the sensor and tone ring. With the second method you bring the tone ring closer, but that is as close as it can get.
If someone were really adventurous, he could take some material out of fixation lug on sensor enabling the sensor to go deeper in and that would make it possible without machining the spindles.
The spindles are massive cast item, grinding off few tenths of mm won't make any difference to it, trust me. Other cars have that much thinner to begin with and none of them lost wheel

Hey guys, yes, even the FRP has to have the rear faces machined to ensure the correct 1.6mm gap between tone ring and sensor.

You can get away with angles Puma sensors, but it’s a hack job! This is a working sensor from when I got my FRP. Not even bolted in but no error on the dash!

Oh, and also proper Focus Mk1 calipers don’t foul the beam, but ST150 Fiesta ones do. Only subtle differences between the handbrake pivots but it matters. You could just ‘fettle’ both the beam and pivot with nominal effort.

Wild E. - Sorry my mistake when I read your guide I assumed it was across the whole back face. It makes more sense now. Can I ask why you removed the o-ring from the bottom of the spindle when you did the second method?

XAF - Thank you for clarifying that. Just to double check though is it 1.6mm or 0.6mm the gap has to be? Also saved me some hassle as I was about to push the button on some ST150 rear callipers but I will source focus ones now. If trimming the beam is so easily avoided its a no brainer in my opinion. I assume the hubs and spindles are the same across the fiesta and focus though with just the callipers being different?

A separate question since its still relevant. Does anyone know the required length for the rear brake hose and what size the fitting are?

Thanks all
Paul Z

Hi Paul
In the absence of James being on line the sensor gaps are 0.6 mm and the threads on the brakelines are M10 fines but I just bought goodridge braided from GBS at ollerton but , unfortunately I can't remember whether they are the short ones or the long ones. Don't forget you will also need a Fiesta ST MK6 hanbrake cable.
Barry

Thank you, I had emailed Goodridge direct and they are happy to make the correct hoses I need for no additional cost, just wanted to double check. I could order 4 of the front hoses with them really as they seem to be long enough and use the same fittings.

Yup got that on the list thanks.
Paul Z

PaulZ said:

Wild E. - Sorry my mistake when I read your guide I assumed it was across the whole back face. It makes more sense now. Can I ask why you removed the o-ring from the bottom of the spindle when you did the second method?

Click to expand...

Hiya mate,

The tone rings are fouling them this way. You put them on top the dust shields and they go in so deeply that they are rubbing agains the rubber.

Regarding your second question, I had my brake hoses bespoke made and IIRC the length was 11 cm and that was spot on

Perfect. Thank you

Paul Z

Can anyone confirm if the hubs and spindles are the same for the focus and fiesta?

Paul Z

eCat shows the same finis for the hubs being 1142082. So, they are.

(as English is not my native, I am maybe saying it wrong. The part which bolts to the rear suspension and onto which the turning part slides onto is the same).