Rear 5-lug rotor and caliper - identify?, Just want to make sure what I've got before I order pads Options

[chmillman]

As per previous threads, my car has had a 5-lug conversion - I think correctly done. The front hubs/rotors/calipers are 914-6/early 911 ones as far as I can tell (ATE calipers), I therefore assume the rear hubs/rotors/calipers might also 914-6 or similar? Can someone confirm? TIA



Just for laughs, Google's Ai analysis of the photo tells me it's from a Nissan Primera P12... (IMG:style_emoticons/default/lol-2.gif)

[peteyd]

those are 4 cylinder calipers. later ones with the dual bleeders.

[chmillman]

OK, so they changed the hubs and rotors for 5-lug… but the 5 lug rotor has basically the same dimensions overall as the 4-lug one, so it fits with the stock -4 caliper? Is that how it works?

[brant]

OK, so they changed the hubs and rotors for 5-lug… but the 5 lug rotor has basically the same dimensions overall as the 4-lug one, so it fits with the stock -4 caliper? Is that how it works?

pretty close...
if you stay with non vented rotors... the OD of the 5bolt rotor gets turned down a tiny amount... to work on a 4 cylinder set up.

[chmillman]

pretty close...
if you stay with non vented rotors... the OD of the 5bolt rotor gets turned down a tiny amount... to work on a 4 cylinder set up.

OK, that's interesting, thanks... Just trying to understand all what has been done here. The disc does have a part number on it - 901 352 401 18 - and it does appear to be a 914/6 disc...





The OD of the rotor part is around 285mm (11.2") as well as I could measure while still on the car. From the traces on the edge of the rotor, it appears that it might even be rubbing slightly on the spring clip... So maybe these weren't turned down?



Anyone have the outer diameter specs for a /4 rear disc vs a /6 disc? Doesn't look like much could or should be turned off, the pad-swept area on the rotor starts in about 3mm from the outer edge.

Also have been unable to find a part number on the rear caliper, just the ATE logo... Here's what it looks like from the inside. Definitely dual bleeder fittings.

[mate914]

914-6 = 911T same rear rotor until the rear vented discs came out.

[Montreal914]

Here you go. (IMG:style_emoticons/default/smile.gif)

914 Rear rotor:
solid
diameter: 282mm
thickness: 9.4 (or 9.5?)mm
caliper piston dia: 33mm

914-6 Rear rotor:
solid
diameter: 286mm
thickness: 10.4mm
caliper piston dia: 38mm

914-6 GT Rear rotor:
vented
diameter: 286mm
thickness: ?
caliper piston dia: 38mm (same caliper as 914-6 with a spacer)
No longer available but there are ways around

[chmillman]

Here you go. (IMG:style_emoticons/default/smile.gif)

914 Rear rotor:
solid
diameter: 282mm
thickness: 9.4 (or 9.5?)mm
caliper piston dia: 33mm

914-6 Rear rotor:
solid
diameter: 286mm
thickness: 10.4mm
caliper piston dia: 38mm

914-6 GT Rear rotor:
vented
diameter: 286mm
thickness: ?
caliper piston dia: 38mm (same caliper as 914-6 with a spacer)
No longer available but there are ways around

OK, great info, thanks much! So it looks like /4 calipers manage to accomodate the extra 1mm thickness of the /6 rotors - unless the pads were shaved in my case - but the extra 4mm in diameter is just a tad too much. Too bad. Options are change the calipers or remove the rotors and turn them down. Unfortunately my toolmaker's lathe is too small for me to be able turn the rotors myself.

[chmillman]

So, I'm thinking at some point I will just want to replace the 914-4 rear calipers with the 914-6 (911T) ones. I have read a lot here about how hard the 914-4 rear calipers are to bleed and get adjusted correctly. Do the 914-6 rear calipers have the same difficulty?
TIA

[brant]

So, I'm thinking at some point I will just want to replace the 914-4 rear calipers with the 914-6 (911T) ones. I have read a lot here about how hard the 914-4 rear calipers are to bleed and get adjusted correctly. Do the 914-6 rear calipers have the same difficulty?
TIA

just the same difficulty.
the bleeding challenge is usually due to the rear brake bias/safety valve that both cars have the same.

911T rear calipers have a different E-brake than a 914/914-6 version which have an internal E brake. Thus the reason the 914/6 version is hard to find/expensive

a 911 style of E-brake can be added, but more weight, more fabrication, and more expense.

[chmillman]

just the same difficulty.
the bleeding challenge is usually due to the rear brake bias/safety valve that both cars have the same.

911T rear calipers have a different E-brake than a 914/914-6 version which have an internal E brake. Thus the reason the 914/6 version is hard to find/expensive

a 911 style of E-brake can be added, but more weight, more fabrication, and more expense.

Ahhh... OK, back to square one... or round one... (IMG:style_emoticons/default/sad.gif)

[chmillman]

Well, not quite square one as it seems. As a follow up to my e-mail query on their pads, PMB informed me that they have new repro 914-6 rear calipers available again…! Posting this for anyone who might need/want them. Interesting that although someone said that all /6 calipers are single bleeder, these have been made as dual bleeders.

https://pmbperformance.com/products/reprodu...h-dual-bleeders

The price even on sale almost made me fall out of my seat, but I guess that’s what one has to pay for rare items… Tough decision. My heart really wants this car to have the /6 brakes on all four corners, my pockets are saying “Woah…!”

Edit: in looking at the parts catalog, I see that the sheet metal backing plates have different part numbers between /4 and /6 - not sure what I have in there now, if they are /4 plates, will I need to change those too?