L320 brake hoses

[hardhead320]

I was looking through old posts gathering info for a brake update on my 65 L320 and ran across Zenndogs old post from 4-08. I ordered the hoses first for front and rear, when I recieved them the rear went right on no problem but the front was a different size thread and would not fit. The Beck/Arney part # 0731188, that hose is M10 x 1.0 metric. The existing hose on the trucks front brakes is 3/8 x 24 standard. Which is correct? Have the front wheel cyclinars been swapped to something else from the datsun world that is 3/8 x 24 thread. The hard brake line coming from the master cyclinder is also 3/8 x 24. Which one's correct?

[DanielC]

The original brake fittings on a 521 are 3/8 x 24. I believe the switch to metric was made with the 620 trucks, so I think the 320 should be the 3/8 x 24.

I did some work on the rear brakes on one of my 521 pickups, and found a wheel cylinder that had the metric threaded fitting, and the previous owner had put in a custom brake line that had a 3/8 x 24 flare nut on one end, and a M10 x 1 flare nut on the other end.

[zenndog]

Wow, I am sorry to hear that you had a problem, I replaced all the wheel cylinders as well when I did my brake rebuild and I think all the parts were Beck/Arney. The only part I had a problem with during my work on the brakes was the rear grease seal which was different on the 520, but it was the same as the front grease seal. I think I posted it. This shouldn't make a difference but there are also two wheel cylinder bores available, I went with the larger bore(more braking force?). I also swapped to a 620 dual master cylinder, That was metric but I just made custom lines with metric fittings on the side of the line attached to the master. Maybe someone put metric 620 cylinders on the front? The 320's are "mainly" standard, but Murphy's law dictates that there will always be a metric thread when least expected!