{"product_id":"valve-pressure-regulator-bx421-bx427-mx450-mx470","title":"Pressure Regulator Valve BX421, BX427, MX450 \u0026 MX470","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\n\u003cp\u003eModified high-pressure by-pass valve. HydraMaster part number 000-169-083, listed as \u003cem\u003eValve, Hi PSI By-Pass — Modified\u003c\/em\u003e and, in the suggested spares schedule, as \u003cem\u003evalve, mod. hi pressure bypass\u003c\/em\u003e.\u003c\/p\u003e\n\u003cp\u003eThe by-pass valve is what sets solution pressure. It holds the pump's output at the set point and dumps the excess back to the water box. Almost every pressure complaint on a truckmount comes back to this valve, the pump, or a restriction — and the by-pass is the cheapest of the three to check.\u003c\/p\u003e\n\n\u003ch2\u003eWhat it fits\u003c\/h2\u003e\n\u003cp\u003eNamed in the parts lists of:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHydraMaster \u003cstrong\u003eBoxxer 427\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eHydraMaster \u003cstrong\u003eMAXX 450D \/ 470D \/ Diesel\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eHydraMaster \u003cstrong\u003eCM402\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eHydraMaster's suggested spares schedule lists it against the \u003cstrong\u003eBoxxer 421\u003c\/strong\u003e, \u003cstrong\u003eBoxxer 427\u003c\/strong\u003e and \u003cstrong\u003eMAXX 450D \/ 470D\u003c\/strong\u003e. CCW's own record adds the \u003cstrong\u003eMAXX 470\u003c\/strong\u003e and covers the BX421, BX427, MX450 and MX470.\u003c\/p\u003e\n\n\u003ch2\u003eService parts for this valve\u003c\/h2\u003e\n\u003cp\u003eA by-pass valve that will not hold pressure does not always need replacing. CCW stocks its wear parts:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/ball-ss-bypass-valve-169-083\"\u003e\u003cstrong\u003e169-204\u003c\/strong\u003e — Ball, stainless steel, for by-pass valve 169-083\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/o-ring-set-hydramaster-pressure-regulator\"\u003e\u003cstrong\u003e097-028\u003c\/strong\u003e — O-ring kit\u003c\/a\u003e (listed for by-pass valve 169-101, and worth checking against your valve)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eHydraMaster also list \u003cstrong\u003e155-021\u003c\/strong\u003e, the red 0–1000 psi by-pass spring, for the CDS 4.8 and SpitFire 3.2. It is not currently a stocked CCW line — ask us if you need one.\u003c\/p\u003e\n\n\u003ch2\u003eHow by-pass faults present\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure reads correctly at rest and collapses under trigger\u003c\/strong\u003e — worn seat or ball. This is the classic by-pass symptom.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure will not reach the set point at all\u003c\/strong\u003e — could be by-pass, could be pump. Check the by-pass first; it is cheaper to rule out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure creeps up or hunts\u003c\/strong\u003e — a ball not seating cleanly, often because of debris rather than wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCannot adjust pressure any more\u003c\/strong\u003e — spring or seat.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eDebris in the seat is the most common single cause, and it usually arrives because the ¼ inch Y strainer screen upstream has been neglected. Fix the cause as well as the symptom.\u003c\/p\u003e\n\n\u003ch2\u003eFitting advice\u003c\/h2\u003e\n\u003cp\u003eNote the pressure setting before you touch anything. It is far easier to return to a known figure than to find it again by trial.\u003c\/p\u003e\n\u003cp\u003eDepressurise the system before you open the valve.\u003c\/p\u003e\n\u003cp\u003eCheck the ball and seat while it is apart — a pitted seat will not seal against a new ball, and at that point the valve is finished rather than serviceable.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003ch3\u003eShould I repair or replace?\u003c\/h3\u003e\n\u003cp\u003eTry the ball and seals first unless the seat is pitted or the body is damaged. Ask us and we will help you decide.\u003c\/p\u003e\n\u003ch3\u003eIs this the same as 169-101?\u003c\/h3\u003e\n\u003cp\u003eNo. 169-101 is the by-pass valve listed for the CDS 4.6\/4.8 and SpitFire 3.2. This one is the modified high-pressure by-pass for the Boxxer and MAXX machines.\u003c\/p\u003e\n\u003ch3\u003eWhat pressure range does it cover?\u003c\/h3\u003e\n\u003cp\u003eHydraMaster does not state the valve's adjustment range in the documentation we hold, and we are not going to publish a figure we cannot verify. Ask us if you need the specification.\u003c\/p\u003e\n\u003ch3\u003eMy pressure collapses under trigger. Is it this valve?\u003c\/h3\u003e\n\u003cp\u003eThat is the classic by-pass symptom, yes — but check the Y strainer screen and the orifice first, because a restriction reads similarly and costs nothing to rule out.\u003c\/p\u003e\n\n\u003chr\u003e\n\u003cp\u003eChasing a pressure fault? Tell us the machine and exactly what the gauge does at rest, at trigger and on by-pass, and we will help you narrow it down before you order anything.\u003c\/p\u003e","brand":"Hydramaster","offers":[{"title":"EACH","offer_id":43830644506837,"sku":"169-083","price":591.43,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2179\/6391\/products\/Pressure-Regulator-Valve-BX421-BX427-MX450-MX470.jpg?v=1780551446","url":"https:\/\/ccwonline.com.au\/products\/valve-pressure-regulator-bx421-bx427-mx450-mx470","provider":"Carpet Cleaners Warehouse","version":"1.0","type":"link"}