EricRyan

iTrader: (4)

Last night, I took my stock downpipe/pre-cat out to replace the crush washers for the banjo bolt and coolant line that goes to the secondary turbo. I bought 2 spec crush washers and replaced the old/visibly warped ones. Torqued down the banjo bolt with the new washers. Rebolted the downpipe back up. Refilled radiator system. Test startup: Failure, still leaking fast from secondary turbo banjo bolt.

The leak has been consistent as far as location. The leak originates from the opposite side of the head of the banjo bolt (where the threads are)

I repeated the unbolting and dropping of the downpipe 2 more times. 1st time to inspect the integrity of the new crush washers, they are okay, I took some 2000 grit to both sides of to smooth them out and remove some gunk that was impressed in there. Still failed. 2nd time I inspected the integrity of the head of the line and the recieving end on the turbo assembly itself, very rough surface from what I could feel/see. Took 2000 grit with adhesive backing, taped it to a table knife and sanded down all rough surfaces on both the turbo assembly and the coolant line. Failure, but less of a leak.

I drop it one last time to inspect the integrity of the banjo bolt. I spin it around slowly between my fingers. I notice a roughly 5 degree warp where the threads start. I also notice that the banjo bolt is man-made, not machined. The drill outs are very sloppy at best. I then notice by sighting down the threads that whoever drilled out the 2 holes nearest the threads, made a very visible "bridge" where liquid could so easily hop over what's left of the ending thread they destroyed.

So I've got 2 holes on the banjo bolt that could easily pass water over into the threads, wind down the threads, then escape from the inner-most crush washer.

Is this solely a problem with the banjo bolt? Or am I looking at a more serious problem? I didn't get to take pictures, but I did a google image search for a banjo bolt so I can kind of draw out what I'm talking about in Paint.

White94RX

I'd get a new bolt and line.

In BMW world, our power steering lines with banjo bolts leak pretty typically after awhile. replacing the crush washers doesn't usually fix it. we always use a new line and new crush washers.

chinaman

I would start off with a new banjo bolt.

GoodfellaFD3S

iTrader: (213)

That sucks. Helluva lot of work, I feel bad for you. New oem banjo bolt, without a doubt.

Gadd

The threads on a banjo bolt have nothing to do with the seal, the crush washers seal to the bolt head and banjo fitting and banjo fitting to surface of the turbo housing. Check the sealing surface of the banjo fitting closely, it can be deformed ( kind of coned in ) from being over torqued. Also inspect the brazing where the fitting is attached the hard line, I've seen them leak there.

If you have a air compressor or can borrow one, you can bench test the turbos for leaks with some 3/8 inj fuel line and a couple of air fittings. 20psi will be plenty.

EricRyan

iTrader: (4)

13 1/2 hours including 2 food stops that night. But you guys are on the right track, I will go with a new OEM bolt as soon as Mazda opens up Tuesday morning. Then I'll go from there if need be. Thanks guys.

DaleClark

iTrader: (55)

Man, I feel for ya - that's a lot of work! But kudos to perservering and doing the job right!

The banjo bolt might have been corroded or something too. That's really weird. Also very good thing that it wasn't the one on the inside!

I'm not 100% sure if that part is available from Mazda - some of the turbo parts are considered part of the turbos themselves. If so, let me know - I've got some good spares.

Dale

DaleClark

iTrader: (55)

I take that back - part number is 99369-1400, should be about $5-6.

Dale

EricRyan

iTrader: (4)

Awesome! How did you get that? Is that the part number for the banjo bolt or the coolant line? If you've got spare banjo bolts that are Mazda spec I might have to buy one or two from you since the head of parts here at our local Mazda insisted that my RX-7 was a Camaro from about 50 feet away. (True story) They always manage to order the wrong parts as well. I'll order one from them Tuesday, and if it's obviously not the bolt I need, I will return/refund it and then talk to you about buying some spares.

IRPerformance

iTrader: (41)

I like to hit all the surfaces the crush washers touch with an angle grinder and sanding wheel. Sometimes there is alot of coolant or oil residue that compromises the seal. ALWAYS use new crush washers. Once they are tightened they cannot be used again reliably. Get a new banjo bolt too. It its on the inside of the turbos it would suck to have to pull them off again if it leaks. The bolts are only like $12 from Malloy Mazda.

DaleClark

iTrader: (55)

That's the part number for the banjo bolt itself. Also, time to stop talking to your parts guy and call Ray at Malloy Mazda - 888-533-3400. He's a VERY sharp parts guy, FD owner, and will get you the right part for a VERY fair price.

Dale

EricRyan

iTrader: (4)

Banjo bolt - $6.95
Crush washers - $4.30 each
-----------------------------------
Total - $16.73

Comes in Friday, I guess the price is worth it for OEM.