Princess 4 pot brake pipe arrangement.

[X flow Eddie]

Hi all, i will be fitting princess 4 pot front brakes to my mk2 escort, question is 2 or 3 " old hand " rally chaps round here that had clubman spec mk2 rally cars in the day have all told me that you must use 2 brake pipes to feed the calipers as they were on the princess as they just dont work as well as feeding one inlet pipe and using a crossover pipe into anouther bleed nipple.  What are people's thoughts on this ?

Regards Eddy 

[Rally Pack 2000]

I bought a brake line fitting kit for mine that just including little crossover pipes and it was a great setup. Some do pipe them in independently as well. I have never heard issues with either method before. I suspect in racing the separate plumbing would be better but for a road car the other is adequate.

[katana]

I guess the old skool thinking was one side would pressurise first then apply pressure to the other side if plumbed with the crossover pipe? A single line to a tee then feed to either side should obviate this but as RP2000 says most people wouldn't notice the difference and it certainly simplifies the bulky plumbing of the alternatives.

[DT36]

Pressure will be equal at all points even with a crossover pipe. 

Even if the first piston is fed momentarily before the crossover point, there is no pressure there until the second piston is fed and pressure starts to rise and equalise at both pistons. This is assuming that the crossover pipe is the same internal diameter as the feed pipe. 

Hydraulic fluid will always take the path of least resistance and pressure will be  equal at all points of an enclosed unit. 

With both pistons being the same size and diameter, it will take the same equal force to move them over a given distance. 

Bit long winded, but hopefully that makes sense. 

[colr6]

Just to summarise, won’t make any difference. Not that you’d notice anyway 🙃

[katana]

Thanks dt36 - didn't say 'old skool' thinking was correct just commenting on the probable thinking behind it 

[deltamal]

Iv'e got the crossover pipe on mine and it's been fine for about 20 years or so! I did get them rebuilt by Big Red a few years ago - just because they were old........

[X flow Eddie]

On 27/05/2020 at 12:17, deltamal said:

Iv'e got the crossover pipe on mine and it's been fine for about 20 years or so! I did get them rebuilt by Big Red a few years ago - just because they were old........

Big redd did mine to !! They did a spot on job as well 👍

[Tubbs]

Hello glad to hear some positive feedback about princess calipers as I'm thinking of using these myself. Had a mate years ago who had them on a rally escort who thought they were the nuts , just a bit heavy.