I have a 1993 SR5 Hilux. Last year the dump pipe on the aftermarket turbo burned through and I had a new one fabricated and fitted. Coming home last Monday the brakes went soft and warning light came on. As I didn't have far to go I topped the reservoir and drove home. I took it to my service centre to be serviced and to find the brake problem. To cut a long story short, the clamp on the dump pipe wore through a metal brake tube. Secondly, the dump pipe did not fit exactly like the old one and the service mechanic had to remove a small section of the inner guard to allow them to remove the oil filter.
Good on you to the local exhaust centre!!