Deore 4-pot Caliper compatibilty

Currently have m506 brakes with the ‘59’ hose and M447 Caliper. My rear Caliper has started leaking and needs replaced. Would it be possible to replace just the Caliper with the new Br-Mt520 4 pot calipers? Or would it not work with the rest of the current set up?

I use them with m477 levers if that helps .

Sounds promising.

Do you know what your hose is? Bit confused between the 59 version and 90 version and banjo vs straight connection. I think I currently have the 59 hose with straight connection caliper fitting.

Looking at the Shimano specs for the 4 pots they’re the straight connection but recommend the 90 hose?

Bh59 v 90 – the 59 is the big bore hose, 90 small bore. For pretty much all newer brakes inc. the 4pot deore you need the 90 I believe (I imagine the  80 works too). I think it comes with all the various fittings you just chop the banjo off, but don’t quote me on that.

Cheers Ben. Spent a bit of time reading about the 59 vs 90 hose. There’s various connection types and and as you say the main difference is internal diameter. 2.3mm for the 59 vs 2.1mm for the 90.

Ive also read a few forum posts where people have reported using the 59 where officially the 90 is recommended (obviously the version with the same connections) and have reported it worked fine. Potentially just a bit less bite power but feedback suggests this is minimal in practice. Also seen a few bits about shimano originally speccing the 59 hose on their road hydro discs to give a more ‘road feel’ but then also specced versions with the 90 to give a bit more bite.

If this is right, I’m tempted to order and give it a try with the 59 hose as the other connections are the same. If it’s crap can order the 90 hose later and will still be cheaper than a full brake set.

Will have a bit more of a read around but tempted to try it.

I bought the 4 pots complete to replace the 477. But a week after fitting them my bike fell of a chairlift and the new lever broke.

To keep riding I refitted the 477 lever  didn’t change the olive  just gave it quick bleed and working fine

Just to update this, ordered a pair of the deore mt-520 4 pot calipers from Bike24 which arrived today.

Swapped out the existing M447 calipers, which had the straight fitting rather than banjo fitting, and as this was the same as the new 4 pots too, it was a direct swap.

I decided to try it with the existing ‘59’ hose rather than the ‘90’ that Shimano recommend. Gave both ends a bleed and all seems fine.  Had a very quick blast down the street just to test them. First impressions were good! Feel less on/off than the 2 pot M447s which may be due to the wider bore of the cable, but if I slammed on the anchors there was loads of power.

Looking forward to a trail ride after the pads have bedded in properly to get a better feel for the overall performance.

Got a set of the callipers here that I was going to sell but now contemplating building them up but I’ma bit clueless on the different levers and hose compatibility…

Any reason these wont work: https://www.bikeinn.com/bike/shimano-hydraulic-disc-brake-lever-deore/136938236/p?utm_source=google_products&utm_medium=merchant&id_producte=7512824&country=uk&gclid=CjwKCAjwvbLkBRBbEiwAChbckZAeqhbY5lzEpbA8VN310aFST2j_noBu4g7k7AhtRdR5lKBVxXVrkBoCfKMQAvD_BwE&gclsrc=aw.ds

Compatibility chart here

http://productinfo.shimano.com/download/pdf/com/2.7/en

Think you should be fine with that lever. I’m using an even older M506 lever with these calipers and it works well. Just need to use the correct hose. You’ll need the BH90-SS as both the lever and caliper are the ‘straight’ fitting.

I’ve got Deore 2-pots fitted at the moment. I’ve bought some 4-pot calipers to fit to my existing levers. How do I know which hoses I’ve got and what difference does it maaaaaike?

The hose should have a number on it somewhere, either 90 or 59. 90 is what’s recommended but on my setup I’ve been using the 59 hose that I had as it had the right connections already I.e. straight fitting as opposed to banjo.

The 59 has a wider internal diameter so is deemed ‘standard power’ vs the 90 hose which has a narrower internal diameter and is ‘high power’. In practice the 59 works, but it does have a little dead travel at the begging of the lever throw before the power comes on and that’s about all I’ve noticed. I am just toying with swapping the hoses to the 90s before a trip to wales next month to see what difference that makes. I’ll update this if I do.

Thread resurrection! Got some Deore M615 brakes on my Anthem. Being a somewhat heavier rider (17.5 stone), I’ve often felt like a bit more power wouldn’t be a bad thing. Am I correct in my understanding that I can switch out the calipers for 520s and just make sure I have the right type of fittings (straight not banjo, and if not huy some straight ones) and can use a 59 hose (though a 90 would be better). Also, do they use the same adaptors?

Any thoughts/advice gratefully received.

M615s use the same SM-BH90-SS hose as recommended on the 520 calipers so should be straight swap and the fittings should be the same (straight rather than bonjo). Only issue you have is 615s are compatible with the ‘wide’ rotors but the 520s need the ‘narrow’ so you’ll need to swap rotors too.

I’m the OP and just to update I’m still using this set up with the 59 hose by the way and it’s totally fine. Never bothered to switch to the 90 hose.

Okay, so it’s a relative piece of cake, other than having to get thinner rotors (is that right?) Not an issue though as going to move up to 203mm on front anyway. Good to hear about the hose, did you need to do anything regarding fettling the levers?