Hi everyone,

I have a -98 XJR, on wich im planing to mount the big "R-Brakes" that the XJR-100 was equipped with from factory.

My question is regarding the 355 mm discs in front and the 330 mm discs in rear: Does these discs/rotors fit the "regular" hubs straight on, without any mods?

I know that the Brembo R-Calipers are pretty tough to find second hand, but if im not wrong, the XKR-R-Calipers will fit, if one can build new Caliper-brackets.

Thanks in advance, Regards Kimmo/Sweden

 

Hi Kimmo, Welcome to the forum:

Almost, on the rear you need to slightly modify the splash shields by cutting about 5mm of the lip
On the front the splash shields need to be removed.
You can then either run the car without shields or install the Brembo specific shields:
MXD1932AA and MXD1933AA

 

also you need the bigger rims...the stock XJR rims won't fit the bigger brakes...you can get all the R spec spare parts you need from http://www.britishparts.co.uk/

even though the are in the UK...it is the still the cheapest place for us Yanks to the R Spec parts

 

Thanks for your answers!

I think i will remove the shields, although im not sure yet. The reason for my question regarding these rotors/discs, is because i saw on the Britishparts homepage(I will order the rotors from here) that it was a different wheel-hub for the Brembo-equipped cars. What is the differens here...?

I have not decided yet if i will use the OEM Jaguar R-Calipers(Very hard to find, i only found the rear-calipers at BP), or if i will go for Porsche´s Brembo-Calipers. I have built big brakes with Porsche´s Calipers before, so it really doesnt matter in my opinion. I will get them repainted and rebadged if so.

I have 19-inch wheels already, modified a bit for my Jag. They are 9,5-19´ all around with 265-30-19 in all corners. Looks very nice!

Im new here so i dont know how to attach pictures...

Best Regards Kimmo/Sweden.

 

I think the difference in hub is because the bolts go through the hub and bolt directly to the Brembos - the standard hubs have threads so the bolts go from the standard caliper and bolt to the hub. I hope that makes sense!
To be honest, there's marginal performance upgrades with the kit, I went with 6 pot monobloc Alcon calipers on the front and 4 pots on the rear of my 100 after a few "issues" with the Brembos. My advice, don't bother, it's mostly for the "look"....if you want proper brakes, get AP Racing or Alcon.

 

Sean;

Yes and no, as you know the rear calipers do not require any modifications to the hubs and on the front the earlier calipers neither.
Only the later front calipers require to tap the mounting holes.
Jaguar explanation for different hubs, which by the way are not different at all but simply have closer tolerances is that fixed calipers require closer tolerances than floating calipers.

As for "marginal performance upgrade", I disagree.
While that is true under "normal" driving, once you push the car the upgrade is quite evident.
Not only does the pedal feel is much better ( could be due to the different hoses more than anything else) but the larger rotors provide more torque ( it's simply a matter of leverage) and the combination is pretty much fade free, which is the main issue with the regular floating calipers under severe service.
That said i agree that Alcon must be the best calipers around. It's what I use on my race car.

 

Kimmo:

You should use the earlier calipers (silver with red Jaguar name) from a "silverstone" XKR model, they are a direct bolt-on.
The front has a calipers to hub bracket and do not require tapping the hub mounting holes;
here are the parts # and prices in british pounds from David Manners:
Note than the price include about 20% VAT, you should be able NOT to pay it for export

Left front caliper JLM21504 price 327
Right front caliper JLM21503 price 327

For the rear you need the calipers that you saw on BP
Left rear caliper MXD2713AA price 458
right rear caliper MXD2712AA price 458

A couple of notes:

BP seems to list prices without VAT, DM list prices with and without VAT.

The rear calipers for the Siverstone were JLM21505 and JLM21506 which have superceded to the MXD numbers and the superceded numbers are listed for the XKR 100.

reason being the the rear are a direct bolt-on regardless of years where in the front the new, XKR 100 calipers will not fit on older cars without tapping the front hubs

 

luc: Thanks for the part numbers!

One thing: How can it be such a big difference in pricing on the big R-discs, depending where u get them?

British Parts JLM21749 - 210,00 Pounds + VAT/Pair,

David Manner JLM21749 - 407,40 Pounds + VAT/Pair,

Are the discs different makes or what is the thing here?

Kind regards Kimmo/Sweden.

 

Kimmo:

DM list 2 parts # for the front, JLM21749 is the factory jaguar discs and JLM21749/1 are after market made by Eurospare of UK ( very good quality)
The Eurospare are only 149 pounds

I bet you that the price from BP is for the Eurospare.

For the rear you need JLM21748 and once again you can either get the original factory or the Eurospare

 

Ok i see, thanks luc!

I saw that you wrote that there was a "Caliper to Hub-Bracket" with these JLM21503 and JLM21504-Front Calipers. Are you sure of this? And they dont require any tapping or machineing of the Hub calipermunting holes?

In that case i think i will order these Calipers from DM.

Although, I have found a set of used(in good shape) XKR Silverstone Calipers here in Sweden, but in the pics i got from the seller, there was no mounting bracket included, only holes in the calipers(wich were placed in regular 90 dgr from the hub holes). To these Calipers i was planing to make new brackets, but if the mountingbrackets are included in the items from DM, then i can order them instead!

Any good steelbraided brakehoses out there that one can get too...?

Big Thanks from Sweden

 

Yes, that is correct the early front calipers come with the brackets mounted ( as a matter of fact Jaguar warn not to remove them since they are carefully set at the factory") and are a direct bolt -on with no drilling/tapping

For brakes lines, you can get a kit designed for the XKR such as:
http://cgi.ebay.co.uk/Jaguar-XK8-SE-...item3efb6af067

but only the rear will fit.
For the front you have 2 choices, either buy the jaguar parts ( very expensive) or, as I did, have a set made by your local race/speedshop

I did the "R" brakes on my 01 XJR and it's why I'm pretty familiar with what you need

 

Definitely do the stainless lines

 

A bit of Happyness - Just found a set of 4 Silverstone second hand(in very good shape) R-Calipers from XKR with mounting brackets.

I picked them up from a carpart-dealer yesterday, payed apx 1200 USD(i think this is a really good price) for all 4 together, and they also included almost new pads.

Although, im gonna strip them down and repaint them in the same Silver color, and put some new badges on. I want them to be 100% like new.

There is mounting brackets to all 4 Calipers, so this is just perfect.

Now i will order the Discs and braided hoses too, it will look and perform great wuth the 19´ BBS-Lemans i have the car equipped with.

Best Regards Kimmo/Sweden

 

Goos news indeed.
if you need new seals to rebuilt them, Jaguar has a kit for both front and rear for pretty cheap. Let me know if you want the part#.

To finish the job correctly you should put the "R" splash shield in front.
Is you car last 6 digits b4 or after 818581?

 

Yes, i will order the front shields with the discs when its time.

Thanks luc! The seals look pretty good, i cant see any leaks or damages in them.

My car is after a later nr than the one you described.

The rear Calipers had a bracket bolted to them in rear also, hope this is correct. My thoghts earlier was that the rear mounting´s were integrated in the calipers, but i saw that there were brackets to these also. Is this correct, or do you have some other caliper-type in rear?

Sorry for my writing in English...

Regards Kimmo!

 

Your English is darn good ( English is not my first language either)

Having a bracket on the rear calipers is correct for an Silverstone.
The later rear calipers do not have a bracket but since the "regular" non-Brembo rear calipers mounting bolts screwed ( meaning the hubs have threads for the bolts) in the hubs , either type can be used without any modification to the mounting holes.
You will see that the front brackets holes are threaded but not the rear bracket. That's why.

For the front splash shields, if you don't want to remove the spindle and ball-joint to mount them, here is what you need to do:
You will see that the shield has a spot-welded little bracket at the bottom which goes between the ball-joint and the hub.
You can cut it ( it's not really needed since you also have 3 bolts mounting the shield) in order to remove the old shield and put the new one.
You will also need to cut a VERY small amount of the shied in order to slide it on the spindle.
Don't worry once you get to it, you will understand what I'm talking about.

 

if you need new seals to rebuilt them, Jaguar has a kit for both front and rear for pretty cheap. Let me know if you want the part#.

Yes please, if you still read this tread, I would really appretiate to have the parts# for the seals kit. In particular the front sets. I'm told by SNGBarrat that Jaguar didn't do seal kits for the Silverstone calipers.......

 

Hi Kimmo:

What Jaguar has is not a seal kit but the dust shields kit.
front JLM21403 and rear is JLM21404.
You need 1 per caliber.
As for the seal/Oring, its pretty simple, they are brembo calipers and a lot of speed shop have seals for them. They just need to know the diameter.
Front for example is 46mm and 48mm ( 2 each per calipers)

 

I did the swap, just be careful how close the car is behind you when stopping suddenly haha.

They are alot more "touchy" than the regular brakes and I noticed a difference immediately.

Most of it is probably the stainless lines but overall it just feels way better to me.

 

Okay, thanks. :-)